.github/pull_request_template.md

@@ -1,51 +0,0 @@
-# Description
-
-Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. List any dependencies that are required for this change.
-
-Fixes # (issue)
-
-## Type of change
-
-Please delete options that are not relevant.
-
-- [ ] Bug fix (non-breaking change which fixes an issue)
-- [ ] New feature (non-breaking change which adds functionality)
-- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
-- [ ] This change requires a documentation update
-- [ ] I have updated the version in `library.properties` to reflect my changes (advance by 0.01 for minor changes, or a whole number for new features)
-- [ ] I have submitted the pull request
-
-# How Has This Been Tested?
-
-Please describe the examples that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration
-
-- [ ] MQ-3
-- [ ] MQ-4
-- [ ] MQ-5
-- [ ] MQ-6
-- [ ] MQ-7
-- [ ] MQ-8
-- [ ] MQ-9
-- [ ] MQ-131
-- [ ] MQ-135
-- [ ] MQ-303
-- [ ] MQ-309
-- [ ] ESP8266
-- [ ] ESP-32
-
-**Test Configuration**:
-* Board:
-* Software (Version of your arduino):
-* Result (Good - Medium - Bad):
-* Your Comments:
-
-# Checklist:
-
-- [ ] My code follows the style guidelines of this project
-- [ ] I have performed a self-review of my own code
-- [ ] I have commented my code, particularly in hard-to-understand areas
-- [ ] I have made corresponding changes to the documentation
-- [ ] My changes generate no new warnings
-- [ ] I have added tests that prove my fix is effective or that my feature works
-- [ ] New and existing unit tests pass locally with my changes
-- [ ] Any dependent changes have been merged and published in downstream modules

CONTRIBUTING.md

@@ -20,7 +20,3 @@ Pull request will be check by three main authors who are linked in
 [REAMDE.md](https://github.com/miguel5612/MQSensorsLib/README.md) and they determine to merge to
 master branch. Later than assessment and debbuging procedures was completed, the contribution 
 will be released.
-
-## Versioning
-
-When making a pull request, please remember to update the `library.properties` file to reflect the changes you've made. If your change is minor, consider advancing the version by 0.01. If you're adding a new feature, you may want to advance the version by a whole number.

Datasheets/MQ131 - sensorsportal.pdf

@@ -0,0 +1,165 @@
+                      MQ131 Semiconductor Sensor for Ozone
+
+    Sensitive material of MQ131 gas sensor is SnO2, which with lower conductivity in clean air. When
+Ozone gas exists. The sensor’s conductivity is more higher along with the gas concentration rising.
+Please use simple electrocircuit, Convert change of conductivity to correspond output signal of gas
+concentration.
+
+    MQ131 gas sensor has high sensitity to Ozone, also sensitive to CL2, NO2, etc.
+
+Character                                                                   Configuration
+
+* Good sensitivity to Ozone in wide range
+* High sensitivity to Ozone
+* Long life and low cost
+* Simple drive circuit
+
+Application
+
+* Domestic Ozone concentration overload Detector
+* Industrial Ozone concentration overload Detector
+* Portable Ozone concentration overload Detector
+
+Technical Data                                                              Basic test loop
+
+           Model No.                        MQ131                           Vc               VRL
+
+         Sensor Type                       Semiconductor
+
+Standard Encapsulation                     Bakelite (Black Bakelite)
+
+         Detection Gas                      Ozone                                                                  RL
+                                                                              VH
+         Concentration                     10-1000ppm Ozone
+                                                                            GND
+           Loop Voltage Vc                  ≤24V DC
+                                                                            The above is basic test circuit of the sensor.
+Circuit    Heater Voltage VH               5.0V±0.2V AC or DC               The sensor need to be put 2 voltage,
+                 Load                            Adjustable                 heater voltage（VH）and test voltage（VC）.
+                                  RL                                        VH used to supply certified working
+                                                                            temperature to the sensor, while VC used
+             Resistance                                                     to detect voltage (VRL) on load resistance
+                                                                            （RL）whom is in series with sensor. The
+               Heater                      31Ω±3Ω（Room Tem.）                sensor has light polarity, Vc need DC
+                                 RH                                         power. VC and VH could use same power
+                                                                            circuit with precondition to assure
+             Resistance                                                     performance of sensor. In order to make
+                                                                            the sensor with better performance,
+                     Heater                            ≤900mW               suitable RL value is needed:
+                                       PH  50KΩ-500KΩ(in 50ppm O3)
+
+                 consumption
+Character
+
+                    Sensing
+                                       Rs
+
+                  Resistance
+
+             Sensitivity S                 Rs(in air)/Rs(in 50ppm O3)≥3
+                                                     (R /R 50ppm 10ppm O3)
+             Slope         α
+                                              20℃±2℃；65%±5%RH
+             Tem. Humidity
+
+Condition Standard test circuit            Vc:5.0V±0.1V；
+                                           VH: 5.0V±0.1V
+
+             Preheat time                  Over 48 hours
+
+Power of Sensitivity body(Ps): Ps=Vc2×Rs/(Rs+RL)2
+
+Resistance of sensor(Rs): Rs=(Vc/VRL-1)×RL
+Sensitivity Characteristics                               Influence of Temperature/Humidity
+
+Fig.1 shows the typical sensitivity characteristics of        Fig.2 shows the typical temperature and humidity
+the MQ131, ordinate means resistance ratio of the sensor         characteristics. Ordinate means resistance ratio
+
+(Rs/Ro), abscissa is concentration of gases. Rs means     of the sensor (Rs/Ro), Rs means resistance of sensor
+                                                          in 50ppm Ozone under different tem. and humidity.
+resistance in different gases, Ro means resistance of      Ro means resistance of the sensor in environment of
+sensor in 50ppm CL2. All test are under standard          50ppm Ozone, 20℃/65%RH
+test conditions.
+
+Structure and configuration
+
+Structure and configuration of MQ131 gas sensor is shown as Fig. 3, sensor composed by micro AL2O3 ceramic tube, Tin
+Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a crust made by plastic and stainless steel
+net. The heater provides necessary work conditions for work of sensitive components. The enveloped MQ-4 have 6 pin, 4
+of them are used to fetch signals, and other 2 are used for providing heating current.
+Notification
+
+1 Following conditions must be prohibited
+1.1 Exposed to organic silicon steam
+
+      Organic silicon steam cause sensors invalid, sensors must be avoid exposing to silicon bond,
+fixature, silicon latex, putty or plastic contain silicon environment
+
+1.2 High Corrosive gas
+
+      If the sensors exposed to high concentration corrosive gas (such as H2Sz, SOX, Cl2, HCl etc), it will
+not only result in corrosion of sensors structure, also it cause sincere sensitivity attenuation.
+
+1.3 Alkali, Alkali metals salt, halogen pollution
+
+      The sensors performance will be changed badly if sensors be sprayed polluted by alkali metals salt
+especially brine, or be exposed to halogen such as fluorin.
+
+1.4 Touch water
+      Sensitivity of the sensors will be reduced when spattered or dipped in water.
+
+1.5 Freezing
+      Do avoid icing on sensor’surface, otherwise sensor would lose sensitivity.
+
+1.6 Applied voltage higher
+
+    Applied voltage on sensor should not be higher than stipulated value, otherwise it cause down-line or
+heater damaged, and bring on sensors’ sensitivity characteristic changed badly.
+
+1.7 Voltage on wrong pins
+    For 6 pins sensor, if apply voltage on 1、3 pins or 4、6 pins, it
+
+will make lead broken, and without signal when apply on 2、4 pins
+
+2 Following conditions must be avoided
+2.1 Water Condensation
+
+    Indoor conditions, slight water condensation will effect sensors performance lightly. However, if water
+condensation on sensors surface and keep a certain period, sensor’ sensitivity will be decreased.
+
+2.2 Used in high gas concentration
+      No matter the sensor is electrified or not, if long time placed in high gas concentration, if will affect
+
+sensors characteristic.
+
+2.3 Long time storage
+      The sensors resistance produce reversible drift if it’s stored for long time without electrify, this drift is
+
+related with storage conditions. Sensors should be stored in airproof without silicon gel bag with clean air.
+For the sensors with long time storage but no electrify, they need long aging time for stbility before using.
+
+2.4 Long time exposed to adverse environment
+    No matter the sensors electrified or not, if exposed to adverse environment for long time, such as
+
+high humidity, high temperature, or high pollution etc, it will effect the sensors performance badly.
+
+2.5 Vibration
+      Continual vibration will result in sensors down-lead response then repture. In transportation or
+
+assembling line, pneumatic screwdriver/ultrasonic welding machine can lead this vibration.
+
+2.6 Concussion
+   If sensors meet strong concussion, it may lead its lead wire disconnected.
+
+2.7 Usage
+   For sensor, handmade welding is optimal way. If use wave crest welding should meet the following
+
+conditions:
+   2.7.1 Soldering flux: Rosin soldering flux contains least chlorine
+   2.7.2 Speed: 1-2 Meter/ Minute
+   2.7.3 Warm-up temperature：100±20℃
+   2.7.4 Welding temperature：250±10℃
+   2.7.5 1 time pass wave crest welding machine
+
+If disobey the above using terms, sensors sensitivity will be reduced.
+

Datasheets/MQ135 - Hanwei.pdf

@@ -0,0 +1,233 @@
+HANWEI ELECTRONICS CO.,LTD                              MQ-135                    http://www.hwsensor.com
+
+TECHNICAL DATA                                                             MQ-135 GAS SENSOR
+
+FEATURES
+
+     Wide detecting scope                     Fast response and High sensitivity
+
+     Stable and long life                     Simple drive circuit
+
+APPLICATION
+
+     They are used in air quality control equipments for buildings/offices, are suitable for detecting
+
+of NH3,NOx, alcohol, Benzene, smoke,CO2 ,etc.
+
+SPECIFICATIONS
+
+     A. Standard work condition
+
+Symbol             Parameter name              Technical condition                Remarks
+   Vc              Circuit voltage             5V±0.1                             AC OR DC
+   VH              Heating voltage             5V±0.1                             ACOR DC
+   RL              Load resistance
+   RH              Heater resistance           can adjust                         Room Tem
+                                               33Ω±5%
+
+PH                 Heating consumption         less than 800mw
+
+        B. Environment condition
+
+Symbol             Parameter name              Technical condition                Remarks
+   Tao             Using Tem                   -10℃-45℃
+
+Tas                Storage Tem                 -20℃-70℃
+
+RH                 Related humidity            less than 95%Rh
+
+O2                 Oxygen concentration        21%(standard condition)Oxygen      minimum value is
+
+                                               concentration can affect sensitivity over 2%
+
+     C. Sensitivity characteristic
+
+Symbol             Parameter name             Technical parameter                 Ramark 2
+Rs                 Sensing                         30KΩ-200KΩ
+                   Resistance                                                     Detecting concentration
+     α                                            (100ppm NH3 )                   scope：
+ (200/50)
+                   Concentration                        ≤0.65                     10ppm-300ppm NH3
+   NH3              Slope rate                                                    10ppm-1000ppm
+Standard
+Detecting                       Temp: 20℃±2℃ Vc:5V±0.1                            Benzene
+Condition                      Humidity: 65%±5% Vh: 5V±0.1
+                                                                                  10ppm-300ppm
+                                                                                  Alcohol
+
+Preheat time                              Over 24 hour
+
+     D. Structure and configuration, basic measuring circuit
+
+            Parts  Materials                                                      Fig.2
+1 Gas sensing      SnO2
+
+           layer   Au
+2 Electrode        Pt
+3 Electrode line   Ni-Cr alloy
+4 Heater coil      Al2O3
+5 Tubular ceramic  Stainless steel gauze
+6 Anti-explosion   (SUS316 100-mesh)
+                   Copper plating Ni
+      network      Bakelite
+7 Clamp ring       Copper plating Ni
+8 Resin base
+9 Tube Pin
+
+Configuration A                               Fig. 1
+
+                                                          Configuration B
+
+                                          A向                                                 A向
+
+      Structure and configuration of MQ-135 gas sensor is shown as Fig. 1 (Configuration A or B), sensor composed
+by micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a
+crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of
+
+TEL: 86-371-67169070 67169080             FAX: 86-371-67169090                E-mail: sales@hwsensor.com
+HANWEI ELCETRONICS CO.,LTD                                 MQ-135            http://www.hwsensor.com
+
+sensitive components. The enveloped MQ-135 have 6 pin ,4 of them are used to fetch signals, and other 2 are used
+
+for providing heating current.
+
+       Electric parameter measurement circuit is shown as Fig.2
+
+       E. Sensitivity characteristic curve
+
+          Fig.2 sensitivity characteristics of the MQ-135
+
+10                                  MQ-135                                   Fig.3 is shows the typical
+                                                                             sensitivity characteristics of
+
+                                                                             the MQ-135 for several gases.
+
+                                                                   AIR           in their: Temp: 20℃、
+                                                                   CO2           Humidity: 65%、
+                                                                   CO
+                                                                   Alc ohol      O2 concentration 21%
+                                                                   NH4           RL=20kΩ
+
+                                                                   Tolueno   Ro: sensor resistance at 100ppm of
+                                                                                 NH3 in the clean air.
+
+                                                                             Rs:sensor resistance at various
+
+Rs/Ro                                                              Acetona   concentrations of gases.
+
+       1
+
+                                                                   ppm
+
+0.1                                     100                        1000
+     10
+
+                   1.8
+
+                   1.6                                             Fig.4 is shows the typical dependence of
+                                                              33%RH the MQ-135 on temperature and humidity.
+                   1.4                                        85%RH Ro: sensor resistance at 100ppm of NH3 in air
+
+       Rs/Ro       1.2
+
+                   1                                                         at 33%RH and 20 degree.
+
+                   0.8                                             Rs: sensor resistance at 100ppm of NH3
+
+                   0.6                                                       at different temperatures and humidities.
+
+                   0.4                  Fig.4
+
+                   0.2                                     degree
+
+                   0
+
+          -20 -10       0       10  20  30     40  50         60
+
+SENSITIVITY ADJUSTMENT
+        Resistance value of MQ-135 is difference to various kinds and various concentration gases. So,When using
+
+this components, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for
+100ppm NH3 or 50ppm Alcohol concentration in air and use value of Load resistancethat( RL) about 20 KΩ(10KΩ
+to 47 KΩ).
+
+         When accurately measuring, the proper alarm point for the gas detector should be determined after
+considering the temperature and humidity influence.
+
+TEL: 86-371-67169070 67169080           FAX: 86-371-67169090                 E-mail: sales@hwsensor.com
+Notification
+
+1 Following conditions must be prohibited
+1.1 Exposed to organic silicon steam
+
+      Organic silicon steam cause sensors invalid, sensors must be avoid exposing to silicon bond,
+fixature, silicon latex, putty or plastic contain silicon environment
+
+1.2 High Corrosive gas
+
+      If the sensors exposed to high concentration corrosive gas (such as H2Sz, SOX，Cl2，HCl etc), it will
+not only result in corrosion of sensors structure, also it cause sincere sensitivity attenuation.
+
+1.3 Alkali, Alkali metals salt, halogen pollution
+
+      The sensors performance will be changed badly if sensors be sprayed polluted by alkali metals salt
+especially brine, or be exposed to halogen such as fluorin.
+
+1.4 Touch water
+      Sensitivity of the sensors will be reduced when spattered or dipped in water.
+
+1.5 Freezing
+      Do avoid icing on sensor’surface, otherwise sensor would lose sensitivity.
+
+1.6 Applied voltage higher
+
+    Applied voltage on sensor should not be higher than stipulated value, otherwise it cause down-line or
+heater damaged, and bring on sensors’ sensitivity characteristic changed badly.
+
+1.7 Voltage on wrong pins
+    For 6 pins sensor, if apply voltage on 1、3 pins or 4、6 pins, it
+
+will make lead broken, and without signal when apply on 2、4 pins
+
+2 Following conditions must be avoided
+2.1 Water Condensation
+
+    Indoor conditions, slight water condensation will effect sensors performance lightly. However, if water
+condensation on sensors surface and keep a certain period, sensor’ sensitivity will be decreased.
+
+2.2 Used in high gas concentration
+      No matter the sensor is electrified or not, if long time placed in high gas concentration, if will affect
+
+sensors characteristic.
+
+2.3 Long time storage
+      The sensors resistance produce reversible drift if it’s stored for long time without electrify, this drift is
+
+related with storage conditions. Sensors should be stored in airproof without silicon gel bag with clean air.
+For the sensors with long time storage but no electrify, they need long aging time for stbility before using.
+
+2.4 Long time exposed to adverse environment
+    No matter the sensors electrified or not, if exposed to adverse environment for long time, such as
+
+high humidity, high temperature, or high pollution etc, it will effect the sensors performance badly.
+
+2.5 Vibration
+      Continual vibration will result in sensors down-lead response then repture. In transportation or
+
+assembling line, pneumatic screwdriver/ultrasonic welding machine can lead this vibration.
+
+2.6 Concussion
+   If sensors meet strong concussion, it may lead its lead wire disconnected.
+
+2.7 Usage
+   For sensor, handmade welding is optimal way. If use wave crest welding should meet the following
+
+conditions:
+   2.7.1 Soldering flux: Rosin soldering flux contains least chlorine
+   2.7.2 Speed: 1-2 Meter/ Minute
+   2.7.3 Warm-up temperature：100±20℃
+   2.7.4 Welding temperature：250±10℃
+   2.7.5 1 time pass wave crest welding machine
+
+If disobey the above using terms, sensors sensitivity will be reduced.
+

Datasheets/MQ2 - Pololulu.pdf

@@ -0,0 +1,176 @@
+           MQ-2 Semiconductor Sensor for Combustible Gas
+
+    Sensitive material of MQ-2 gas sensor is SnO2, which with lower conductivity in clean air. When the
+target combustible gas exist, The sensor’s conductivity is more higher along with the gas concentration
+rising. Please use simple electrocircuit, Convert change of conductivity to correspond output signal of
+gas concentration.
+
+    MQ-2 gas sensor has high sensitity to LPG, Propane and Hydrogen, also could be used to Methane
+and other combustible steam, it is with low cost and suitable for different application.
+
+Character                                                                Configuration
+
+*Good sensitivity to Combustible gas in wide range
+* High sensitivity to LPG, Propane and Hydrogen
+* Long life and low cost
+* Simple drive circuit
+
+Application
+
+* Domestic gas leakage detector
+* Industrial Combustible gas detector
+* Portable gas detector
+
+Technical Data                                                           Basic test loop
+
+                                                                                                                                             T
+
+         Model No.                                        MQ-2           Vc             VRL
+       Sensor Type                                  Semiconductor
+Standard Encapsulation                        Bakelite (Black Bakelite)                                         RL
+      Detection Gas                        Combustible gas and smoke       VH
+                                                    300-10000ppm
+         Concentration                           ( Combustible gas)      GND
+
+           Loop Voltage Vc                             ≤24V DC           The above is basic test circuit of the sensor.
+                                                 5.0V±0.2V ACorDC        The sensor need to be put 2 voltage,
+Circuit    Heater Voltage VH                                             heater voltage（VH）and test voltage（VC）.
+                 Load                                  Adjustable        VH used to supply certified working
+                                  RL                                     temperature to the sensor, while VC used
+                                             31Ω±3Ω（Room Tem.）           to detect voltage (VRL) on load resistance
+             Resistance                                                  （RL）whom is in series with sensor. The
+                                                        ≤900mW           sensor has light polarity, Vc need DC
+               Heater                                                    power. VC and VH could use same power
+                                 RH        2KΩ-20KΩ(in 2000ppm C3H8 )    circuit with precondition to assure
+                                                                         performance of sensor. In order to make
+             Resistance                        Rs(in air)/Rs(1000ppm     the sensor with better performance,
+                                                                         suitable RL value is needed:
+               Heater                              isobutane)≥5          Power of Sensitivity body(Ps):
+                                PH                                       Ps=Vc2×Rs/(Rs+RL)2
+                                            ≤0.6(R5000ppm/R3000ppm CH4)
+           consumption                        20℃±2℃；65%±5%RH
+                                                   Vc:5.0V±0.1V；
+Character Sensing                               VH: 5.0V±0.1V
+                                       Rs           Over 48 hours
+
+                  Resistance
+
+             Sensitivity S
+
+             Slope         α
+
+             Tem. Humidity
+
+Condition Standard test circuit
+
+             Preheat time
+Resistance of sensor(Rs): Rs=(Vc/VRL-1)×RL
+
+ Sensitivity Characteristics                                    Influence of Temperature/Humidity
+                                            Fig1
+                                                                1.9
+Fig.1 shows the typical sensitivity characteristics of
+the MQ-2, ordinate means resistance ratio of the sensor         1.7           Fig2  60%RH
+
+(Rs/Ro), abscissa is concentration of gases. Rs means           1.5                 30%RH
+
+resistance in different gases, Ro means resistance of                               85%RH
+sensor in 1000ppm Hyrogen. All test are under standard
+test conditions.                                         Rs/R0  1.3
+
+Structure and configuration                                     1.1
+
+                                                                0.9
+
+                                                                0.7
+
+                                                                0.5           10 20 30 40 50 ℃
+                                                                   -20 -10 0
+
+                                                               Fig.2 shows the typical temperature and humidity
+                                                               characteristics. Ordinate means resistance ratio
+                                                           of the sensor (Rs/Ro), Rs means resistance of sensor
+                                                         in 1000ppm Butane under different tem. and humidity.
+                                                         Ro means resistance of the sensor in environment of
+                                                           1000ppm Methane, 20℃/65%RH
+
+Structure and configuration of MQ-2 gas sensor is shown as Fig. 3, sensor composed by micro AL2O3 ceramic tube, Tin
+Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a crust made by plastic and stainless steel
+net. The heater provides necessary work conditions for work of sensitive components. The enveloped MQ-2 have 6 pin, 4
+of them are used to fetch signals, and other 2 are used for providing heating current.
+Notification
+
+1 Following conditions must be prohibited
+1.1 Exposed to organic silicon steam
+
+      Organic silicon steam cause sensors invalid, sensors must be avoid exposing to silicon bond,
+fixature, silicon latex, putty or plastic contain silicon environment
+
+1.2 High Corrosive gas
+
+      If the sensors exposed to high concentration corrosive gas (such as H2Sz, SOX，Cl2，HCl etc), it will
+not only result in corrosion of sensors structure, also it cause sincere sensitivity attenuation.
+
+1.3 Alkali, Alkali metals salt, halogen pollution
+
+      The sensors performance will be changed badly if sensors be sprayed polluted by alkali metals salt
+especially brine, or be exposed to halogen such as fluorin.
+
+1.4 Touch water
+      Sensitivity of the sensors will be reduced when spattered or dipped in water.
+
+1.5 Freezing
+      Do avoid icing on sensor’surface, otherwise sensor would lose sensitivity.
+
+1.6 Applied voltage higher
+
+    Applied voltage on sensor should not be higher than stipulated value, otherwise it cause down-line or
+heater damaged, and bring on sensors’ sensitivity characteristic changed badly.
+
+1.7 Voltage on wrong pins
+    For 6 pins sensor, if apply voltage on 1、3 pins or 4、6 pins, it
+
+will make lead broken, and without signal when apply on 2、4 pins
+
+2 Following conditions must be avoided
+2.1 Water Condensation
+
+    Indoor conditions, slight water condensation will effect sensors performance lightly. However, if water
+condensation on sensors surface and keep a certain period, sensor’ sensitivity will be decreased.
+
+2.2 Used in high gas concentration
+      No matter the sensor is electrified or not, if long time placed in high gas concentration, if will affect
+
+sensors characteristic.
+
+2.3 Long time storage
+      The sensors resistance produce reversible drift if it’s stored for long time without electrify, this drift is
+
+related with storage conditions. Sensors should be stored in airproof without silicon gel bag with clean air.
+For the sensors with long time storage but no electrify, they need long aging time for stbility before using.
+
+2.4 Long time exposed to adverse environment
+    No matter the sensors electrified or not, if exposed to adverse environment for long time, such as
+
+high humidity, high temperature, or high pollution etc, it will effect the sensors performance badly.
+
+2.5 Vibration
+      Continual vibration will result in sensors down-lead response then repture. In transportation or
+
+assembling line, pneumatic screwdriver/ultrasonic welding machine can lead this vibration.
+
+2.6 Concussion
+   If sensors meet strong concussion, it may lead its lead wire disconnected.
+
+2.7 Usage
+   For sensor, handmade welding is optimal way. If use wave crest welding should meet the following
+
+conditions:
+   2.7.1 Soldering flux: Rosin soldering flux contains least chlorine
+   2.7.2 Speed: 1-2 Meter/ Minute
+   2.7.3 Warm-up temperature：100±20℃
+   2.7.4 Welding temperature：250±10℃
+   2.7.5 1 time pass wave crest welding machine
+
+If disobey the above using terms, sensors sensitivity will be reduced.
+

Datasheets/MQ3 - Sparkfun.pdf

@@ -0,0 +1,170 @@
+HANWEI ELETRONICS CO.,LTD                               MQ-3                           http://www.hwsensor.com
+
+TECHNICAL DATA                                                            MQ-3 GAS SENSOR
+
+FEATURES
+
+* High sensitivity to alcohol and small sensitivity to Benzine .
+
+* Fast response and High sensitivity
+
+* Stable and long life
+
+* Simple drive circuit
+
+APPLICATION
+
+They are suitable for alcohol checker, Breathalyser.
+
+SPECIFICATIONS
+
+A. Standard work condition
+
+Symbol             Parameter name                       Technical condition                              Remarks
+                                                               5V±0.1                                  AC OR DC
+Vc                 Circuit voltage                             5V±0.1                                  ACOR DC
+                                                               200KΩ
+VH                 Heating voltage                                                                     Room Tem
+                                                               33Ω±5%
+RL                 Load resistance                                                                        Remarks
+                                                          less than 750mw
+RH                 Heater resistance                                                          minimum value is
+                                                                                              over 2%
+PH                 Heating consumption
+                                                                                                       Remarks
+    B. Environment condition                                                                  Detecting concentration
+
+Symbol             Parameter name                       Technical condition                    scope：
+   Tao              Using Tem                             -10℃-50℃                               0.05mg/L—10mg/L
+                                                                                                       Alcohol
+Tas                Storage Tem                          -20℃-70℃
+
+RH                 Related humidity                     less than 95%Rh
+
+O2                 Oxygen concentration                 21%(standard condition)Oxygen
+
+                                                        concentration can affect sensitivity
+
+C. Sensitivity characteristic
+
+Symbol                Parameter name                    Technical parameter
+   Rs              Sensing Resistance                       1MΩ- 8 MΩ
+
+                                                        (0.4mg/L alcohol )
+
+     α             Concentration slope rate                   ≤0.6
+
+(0.4/1 mg/L)
+
+Standard           Temp: 20℃±2℃ Vc:5V±0.1
+detecting          Humidity: 65%±5% Vh: 5V±0.1
+condition
+Preheat time                     Over 24 hour
+
+D. Structure and configuration, basic measuring circuit
+
+            Parts  Materials                                                                  Fig.2
+1 Gas sensing      SnO2
+
+           layer   Au
+2 Electrode        Pt
+3 Electrode line   Ni-Cr alloy
+4 Heater coil      Al2O3
+5 Tubular ceramic  Stainless steel gauze
+6 Anti-explosion   (SUS316 100-mesh)
+                   Copper plating Ni
+      network      Bakelite
+7 Clamp ring       Copper plating Ni
+8 Resin base
+9 Tube Pin
+
+Configuration A                              Fig. 1
+
+                                                         Configuration B
+
+                                                    A向                                                   A向
+TEL: 86-371- 67169070 67169080 FAX: 86-371-67169090
+                                                                                              E-mail: sales@hwsensor.com
+HANWEI ELETRONICS CO.,LTD                            MQ-3                   http://www.hwsensor.com
+
+Structure and configuration of MQ-3 gas sensor is shown as Fig. 1 (Configuration A or B), sensor composed by
+micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a
+crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of
+sensitive components. The enveloped MQ-3 have 6 pin ,4 of them are used to fetch signals, and other 2 are used
+for providing heating current.
+
+        Electric parameter measurement circuit is shown as Fig.2
+
+       E. Sensitivity characteristic curve
+
+                                     MQ-3
+
+100
+
+                                                                            Fig.3 is shows the typical
+
+                                                                            sensitivity characteristics of
+
+                                           Alcohol                          the MQ-3 for several gases.
+
+                                           Benzine                          in their: Temp: 20℃、
+
+                                           CH4                              Humidity: 65%、
+
+10                                         Hexane                           O2 concentration 21%
+                                                                            RL=200kΩ
+                                           LPG
+                                                                            Ro: sensor resistance at 0.4mg/L of
+
+Rs/Ro                                      CO                               Alcohol in the clean air.
+
+                                           Air                              Rs:sensor resistance at various
+
+                                                                            concentrations of gases.
+
+       1
+
+0.1                          1                              mg/L        10
+    0.1
+
+             Fig.2 sensitivity characteristics of the MQ-3
+
+       1.70       Rs/Ro--Temp                                               Fig.4 is shows the typical
+                                                                            dependence of the MQ-3 on
+       1.60                                                                 temperature and humidity.
+
+       1.50                                                 33%RH           Ro: sensor resistance at 0.4mg/L of
+                                                            85%RH              Alcohol in air at 33%RH and 20 ℃
+       1.40
+                                                                            Rs: sensor resistance at 0.4mg/L of
+       1.30                                                                    Alcohol at different temperatures
+                                                                               and humidities.
+Rs/Ro  1.20
+
+       1.10
+
+       1.00
+       0.90
+
+       0.80       Fig.4
+
+       0.70
+
+       0.60                                                       Temp
+       0.50
+
+          -10  0  10     20     30         40               50    60
+
+SENSITVITY ADJUSTMENT
+        Resistance value of MQ-3 is difference to various kinds and various concentration gases. So,When using
+
+this components, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for
+0.4mg/L ( approximately 200ppm ) of Alcohol concentration in air and use value of Load resistancethat( RL) about
+
+200 KΩ(100KΩ to 470 KΩ).
+
+         When accurately measuring, the proper alarm point for the gas detector should be determined after
+considering the temperature and humidity influence.
+
+TEL: 86-371- 67169070 67169080 FAX: 86-371-67169090                         E-mail: sales@hwsensor.com
+

Datasheets/MQ303A - Hanwei.pdf

@@ -0,0 +1,103 @@
+HANWEI ELETRONICS CO.,LTD                            MQ-303A               http://www.hwsensor.com
+
+GAS SENSOR MQ-303A for ALCOHOL DETECTION
+
+      * High sensitivity
+      * Low power consumption
+      * Miniature-size
+
+     The MQ-303A is a tin dioxide semiconductor gas
+sensor which has a high sensitivity to alcohol with quick
+response speed. This model is suitable for alcohol
+detection such as portable breath alcohol checker or
+ignition locking system in automobiles.
+
+Structure
+
+      Gas sensitive semiconductor material is a mini bead type and a heater coil and electrode wire are embedded
+in the element. The sensing element is installed in the metal housing which uses double stainless steel mesh (100
+mesh) in the path of gas flow. The mesh is an anti-explosion feature
+(Fig 1).
+
+Operating conditions
+
+        Fig 2 shows the standard operating circuit for this model. The
+change of the sensor resistance (RS) is obtained as the change of the
+output voltage across the fixed or variable resistor (RL). In order to
+obtain the best performance and specified characteristics, the values
+of the heater voltage (VH) circuit voltage (VC) and load resistance (RL)
+must be within the range of values given in the standard operating
+conditions shown in the Specification table on the next page. Generally,
+the sensor enters into normal working conditions after several minutes’
+preheating, If you connect the sensor heater with a high voltage 2.2 ±
+0.20V for 5-10 sec before normal testing , the sensor shall stabilize and
+enter into normal working conditions quickly.
+
+Sensitivity characteristics
+
+Fig 3 shows the sensitivity characteristics curves of the MQ-303A (typical data). Sensitivity characteristics of the
+gas sensors are expressed by the relationship between the sensor resistance and gas
+concentration. The sensor resistance decreases with an increase of gas
+concentration based on a logarithmic function.
+
+TEL: 86-371-67169070 67169080  FAX: 86-371-67169090                        E-mail: sensor@371.net
+HANWEI ELETRONICS CO.,LTD                                        MQ-303A         http://www.hwsensor.com
+
+A. Standard Operating conditions
+
+Symbol           Parameter                                     Specification          Conditions etc.
+VH          Heater voltage                                     0.9V ± 0.10V            AC or DC
+VC          Circuit voltage                                    Less than 6 V        DC (polarity is important)
+RL          Load resistance                                    Variable             P S < 10 mW
+RH          Heater resistance                                  4.5 Ω ± 0.5 Ω        at room temperature
+                                                               Less than 130 mA
+IH          Heater current                                     Less than 130 mW     IH = VH / RH (typical value)
+PH          Heater power consumption                           Less than 10 mW   P H = V H 2 / R H (typical value)
+PS          Power dissipation of sensing element
+                                                                                 P S = (V C - V RL ) 2/ R S
+
+B. Environmental conditions
+
+Symbol      Parameter                       Specification                        Conditions etc.
+
+Tao         Operating temperature -10 o C to 50 o C
+
+Tas         Storage temp                    -20 o C to 70 o C                    Recommended range
+
+RH          Relative humidity               Less than 70% RH
+
+(O2)        Oxygen concentration            21%±1%(Standard condition)           Absolute minimum level: more then 18%
+
+                                            The sensitivity characteristics are influenced by the variation in oxygen concentration.
+
+C. Sensitivity characteristics
+
+Model                    MQ-303A (tentative specifications)
+
+Symbol Parameter                Specification                           Conditions etc.
+                                (20kΩ to 200 kΩ)                        at ethanol 300 ppm
+Rs          Sensor resistance                                           Rs (at ethanol 300 ppm) / Rs (at ethanol 50 ppm)
+
+β           Sensitivity         (0.50 ± 0.15)                                      Specifications
+                                                                        Should satisfy the
+Standard Test Conditions: Temp: 20 o C ± 2 o C V C : 5.0 V ± 1%         specifications shown in the
+                                                                        sensitivity characteristics.
+                         Humidity: 65% ± 5% V H : 0.9 V ± 1%
+
+                         (in clean air)        R L : 50K Ω ±5%
+
+                         Pre-heating time: more than 48 hours
+
+D. Mechanical characteristics
+
+     Items                      Conditions
+
+Vibration                Frequency: 100 cpm
+                         Vertical amplitude: 4 mm
+                         Duration: 1 hour
+
+Shock                    Acceleration: 100G
+                         Number of impacts: 5 times
+
+TEL: 86-371-67169070 67169080            FAX: 86-371-67169090                    E-mail: sensor@371.net
+

Datasheets/MQ309A - Hanwei.pdf

@@ -0,0 +1,115 @@
+HANWEI ELETRONICS CO.,LTD    MQ309A                      http://www.hwsensor.com
+
+          MQ309A
+
+for CARBON MONOXIDE(CO) and Methane Detection
+
+General Information
+
+MQ309A is a tin dioxide semiconductor gas sensor which has excellent performance in
+detecting both CO and Methane. It is miniature sensor adopt changing working
+temperature periodically to detect with high sensitivity and selectivity, the humidity has
+little influence on it.
+
+Configuration
+
+      Gas sensor sensitivity material is a mini bead, a heater coil and electrode wire are
+embedded in the element this element is installed in the in the metal housing which uses
+double stainless steel mesh(100mesh) with anti-explosion function. As figure1
+
+Operating condictions
+
+      When the gas sensor is operatedwith high/low
+periodic operation (As figure 2), sensor signal changes
+according to its temperature dependency By detecting
+the sensors signal at sufficient timmings (at high
+temperature for methane and at a low temperature for
+CO),selective detection of both methane and CO has
+been achieved. Figs 3 and 3b show the sensitivity
+characteristics of the MQ309A, at high temperature and
+at low temperature signals respectively.
+
+TEL: 86-371-5333098 5333099  FAX: 86-371-5333090         E-mail: sensor@371.net
+HANWEI ELETRONICS CO.,LTD                 MQ309A  http://www.hwsensor.com
+
+A Standard working conditions
+
+Symbol  Parament             Specifications             Remarks
+                                                           AC or DC
+VH(H) Heater voltage high    0.9V ± 0.10V
+                                                        DC (polarity is
+VH(L) Heater voltage Low     0.2 V ? ?5%          important)
+
+VC      Circuit Voltage      =6V                        P S < 10 mW
+                             Adjustable (> 10
+RL      Load resistance      ? ? ?)                     At room temperature
+                             4.0 ? ???1.0 ?
+RH      Heater Resistance    30sec ± 5 sec              Before switching to
+        Heating time hihg    120 sec ± 10sec      Low
+TH (H)  Heating time low     < 1 sec
+TH (L)  Detecting time low                              VH=0.9V
+DT (L)                                                  VH=0.2V
+
+I (H)   Currentconsumption high =80mA                P S = (V C - V RL ) 2/ Rs
+
+I (L)   Current Consumption low 40? ?mW
+
+PS      Power siddipation    =10 mW
+
+TEL: 86-371-5333098 5333099  FAX: 86-371-5333090  E-mail: sensor@371.net
+HANWEI ELETRONICS CO.,LTD                           MQ309A      http://www.hwsensor.com
+
+B. Environmental Conditions
+
+Symbol Parameter               Specification                    Remarks
+                            -20 o C to 50 o C
+Tao     Operating
+
+        Temperature                                             Recommended range
+
+Tas     Storage             -20 o C to 70 o C
+
+        temperature
+
+RH      Relative            95% RH
+
+        Humidity
+
+(O2)    Oxygen              21% 1%(Standard Terms)              Absolute Minimum
+
+        Concentration The sensitivity character are Level: more than18%
+
+                            influenced by the variation in
+
+                            OXYGEN concentration
+
+C. Sensitivity
+
+Mosel                                 MQ-309
+
+Symbol          Parament              Specifications Remarks
+
+Rs              Sensor resistance at  (20k? ??to 200 In 200 ppm CO
+
+                low period            k? )
+
+? ?(100-300)    Sensitivity           1.05 to 2.1               Rs (300 ppmCO) / Rs (100
+                Slope(30-100PPM)                                ppm CO)
+
+   ? ?(3000-5000) Sensitivity slope at Low 0.75 to 1.2                Rs(5000 ppm CH4)
+                                                                      /Rs(3000ppm CH4)
+Standard test Conditions : Temperature: 20 o C ? ?2 o C         V C : 5.0 V ? ?1%
+
+              Humidity: 65% ? ?5%     V H : 0.9 V ? ?1%
+
+                                             R L : 50K ? ?? 5%
+              Preheating time more than 48 hours
+
+HANWEI ELETRONICS CO.,LTD
+
+TEL:+86-371-8732420 8732424 6953352
+FAX:+86-371-8730444 6962121
+Email:sensor@371.net http://www.hwsensor.com
+
+TEL: 86-371-65333098 65333099 FAX: 86-371-65333090              E-mail: sensor@371.net
+

Datasheets/MQ4 - Sparkfun.pdf

@@ -0,0 +1,155 @@
+HANWEI ELECTRONICS                                        MQ-4                 www.hwsensor.com
+
+TECHNICAL DATA                                                              MQ-4 GAS SENSOR
+
+FEATURES
+
+* High sensitivity to CH4，Natural gas.
+* Small sensitivity to alcohol, smoke.
+
+* Fast response . * Stable and long life * Simple drive circuit
+
+APPLICATION
+
+They are used in gas leakage detecting equipments in family and industry, are suitable for detecting of
+
+CH4,Natural gas.LNG, avoid the noise of alcohol and cooking fumes and cigarette smoke.
+
+SPECIFICATIONS
+
+A. Standard work condition
+
+Symbol               Parameter name                       Technical condition   Remarks
+   Vc                Circuit voltage                             5V±0.1        AC OR DC
+   VH                Heating voltage                             5V±0.1        ACOR DC
+   PL                Load resistance
+   RH                                                             20KΩ         Room Tem
+                     Heater resistance
+                                                                 33Ω±5%
+
+PH                   Heating consumption                  less than 750mw
+
+    B. Environment condition
+
+Symbol               Parameter name                       Technical condition                Remarks
+   Tao                Using Tem                             -10℃-50℃
+
+Tas                  Storage Tem                          -20℃-70℃
+
+RH                   Related humidity                     less than 95%Rh
+
+O2                   Oxygen concentration      21%(standard condition)Oxygen   minimum value is
+
+                                               concentration can affect sensitivity over 2%
+
+C. Sensitivity characteristic
+
+Symbol                Parameter name                      Technical parameter           Ramark 2
+   Rs                Sensing Resistance                       10KΩ- 60KΩ       Detecting concentration
+                                                                               scope：
+                                                          (1000ppm CH4 )
+                                                                               200-10000ppm
+
+    α                                                     ≤0.6                 CH4 , natural gas
+(1000ppm/
+                     Concentration slope rate
+
+5000ppm CH4)         Temp: 20℃±2℃ Vc:5V±0.1
+Standard             Humidity: 65%±5% Vh: 5V±0.1
+detecting
+condition
+
+Preheat time                                Over 24 hour
+
+D. Strucyure and configuration, basic measuring circuit
+
+            Parts    Materials                                                 Fig.2
+1 Gas sensing        SnO2
+
+           layer     Au
+2 Electrode          Pt
+3 Electrode line     Ni-Cr alloy
+4 Heater coil        Al2O3
+5 Tubular ceramic    Stainless steel gauze
+6 Anti-explosion     (SUS316 100-mesh)
+                     Copper plating Ni
+      network        Bakelite
+7 Clamp ring         Copper plating Ni
+8 Resin base
+9 Tube Pin
+
+Configuration A                                Fig. 1
+
+                                                           Configuration B
+
+TEL:86-371-67169080           A向                                                               A向
+                     FAX: 86-371-67169090
+                                                                               E-mail: sales@hwsensor.com
+HANWEI ELECTRONICS                                                MQ-4   www.hwsensor.com
+
+   Structure and configuration of MQ-4 gas sensor is shown as Fig. 1 (Configuration A or B), sensor composed by
+micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a
+crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of
+sensitive components. The enveloped MQ-4 have 6 pin ,4 of them are used to fetch signals, and other 2 are used
+for providing heating current.
+
+        Electric parameter measurement circuit is shown as Fig.2
+
+       E. Sensitivity characteristic curve
+
+                                    MQ-4
+
+10
+
+   1Rs/Ro                  LPG                                                            Fig.3 is shows the typical
+                           CH4                                                            sensitivity characteristics of
+0.1                        H2                                                             the MQ-4 for several gases.
+    100                    CO
+                           alcohol                                                               in their: Temp: 20℃、
+                           smoke                                                                 Humidity: 65%、
+                           Air                                                                   O2 concentration 21%
+                                                                                                 RL=20kΩ
+                                        1000                                                Ro: sensor resistance at 1000ppm of
+                                                                                                 CH4 in the clean air.
+                                                                                            Rs:sensor resistance at various
+                                                                                                 concentrations of gases.
+
+                                                                            ppm
+
+                                                                         10000
+
+                   Fig.2 sensitivity characteristics of the MQ-4
+
+                   1.4                  MQ-4                      33%RH
+                                                                  85%RH
+                   1.3                                                   Fig.4 is shows the typical dependence of
+
+                   1.2                                                   the MQ-4 on temperature and humidity.
+
+                   1.1                                                   Ro: sensor resistance at 1000ppm of CH4 in air
+                                                                               at 33%RH and 20 degree.
+       Rs/Ro       1
+                                                                         Rs: sensor resistance at 1000ppm of CH4 in air
+                   0.9                                                         at different temperatures and humidities.
+
+                   0.8                            Fig.4
+
+                   0.7
+
+                   0.6
+
+                   0.5
+
+              -10       0           10  20  Temp  30          40  50
+
+SENSITVITY ADJUSTMENT
+        Resistance value of MQ-4 is difference to various kinds and various concentration gases. So,When using
+
+this components, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for
+5000ppm of CH4 concentration in air and use value of Load resistance ( RL) about 20KΩ(10KΩ to 47KΩ).
+
+        When accurately measuring, the proper alarm point for the gas detector should be determined after
+considering the temperature and humidity influence.
+
+TEL:86-371-67169080                     FAX: 86-371-67169090             E-mail: sales@hwsensor.com
+

Datasheets/MQ5 - Parallax.pdf

@@ -0,0 +1,159 @@
+HANWEI ELECTRONICS CO.,LTD                           MQ-5                                  http://www.hwsensor.com
+
+TECHNICAL DATA                                                             MQ-5 GAS SENSOR
+
+FEATURES
+
+    * High sensitivity to LPG, natural gas , town gas
+
+    * Small sensitivity to alcohol, smoke.
+
+    * Fast response . * Stable and long life * Simple drive circuit
+
+APPLICATION
+
+They are used in gas leakage detecting equipments in family and industry, are suitable for detecting of
+
+LPG, natural gas , town gas, avoid the noise of alcohol and cooking fumes and cigarette smoke.
+
+SPECIFICATIONS
+
+    A. Standard work condition
+
+Symbol             Parameter name                          Technical condition       Remarks
+                                                                  5V±0.1            AC OR DC
+Vc                 Circuit voltage                                5V±0.1            ACOR DC
+                                                                   20KΩ
+VH                 Heating voltage                                                  Room Tem
+                                                                  31±10%
+PL                 Load resistance
+                                                             less than 800mw
+RH                 Heater resistance
+
+PH                 Heating consumption
+
+    B. Environment condition
+
+Symbol             Parameter name                       Technical condition                        Remarks
+   Tao              Using Tem                             -10℃-50℃
+
+Tas                Storage Tem                             -20℃-70℃
+
+RH                 Related humidity                        less than 95%Rh
+
+O2                 Oxygen concentration              21%(standard condition)Oxygen  minimum value is
+
+                                                     concentration can affect sensitivity over 2%
+
+C. Sensitivity characteristic
+
+   Symbol           Parameter name                         Technical parameter               Remarks
+                   Sensing Resistance                          10KΩ- 60KΩ           Detecting concentration
+      Rs                                                                            scope：
+                                                           (5000ppm methane )       200-10000ppm
+     α                                                                              LPG,LNG
+(5000ppm/1000      Concentration slope rate                ≤0.6
+ppm CH4)                                                                            Natural gas,
+Standard           Temp: 20℃±2℃ Vc:5V±0.1                                           iso-butane, propane
+detecting          Humidity: 65%±5% Vh: 5V±0.1                                      Town gas
+condition
+
+Preheat time                              Over 24 hour
+
+D. Strucyure and configuration, basic measuring circuit
+
+            Parts  Materials                                                        Fig.2
+1 Gas sensing      SnO2
+
+           layer   Au
+2 Electrode        Pt
+3 Electrode line   Ni-Cr alloy
+4 Heater coil      Al2O3
+5 Tubular ceramic  Stainless steel gauze
+6 Anti-explosion   (SUS316 100-mesh)
+                   Copper plating Ni
+      network      Bakelite
+7 Clamp ring       Copper plating Ni
+8 Resin base
+9 Tube Pin
+
+Configuration A                               Fig. 1
+
+                                                          Configuration B
+
+                                          A向                                                       A向
+
+Structure and configuration of MQ-5 gas sensor is shown as Fig. 1 (Configuration A or B), sensor composed by
+
+TEL: 86-371- 67169070 67169080 FAX: 86-371-67169090                                 E-mail: sales@hwsensor.com
+HANWEI ELECTRONICS CO.,LTD                           MQ-5                http://www.hwsensor.com
+
+micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a
+crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of
+sensitive components. The enveloped MQ-5 have 6 pin ,4 of them are used to fetch signals, and other 2 are used
+for providing heating current.
+
+        Electric parameter measurement circuit is shown as Fig.2
+
+       E. Sensitivity characteristic curve
+
+          Fig.2 sensitivity characteristics of the MQ-5
+
+10                                MQ-5
+
+Rs/Ro  1                                                                 Fig.3 is shows the typical
+
+                                                                         sensitivity characteristics of
+                                                                         the MQ-5 for several gases.
+
+                                                                             in their: Temp: 20℃、
+                                                                             Humidity: 65%、
+
+                                                                             O2 concentration 21%
+                                                                             RL=20kΩ
+
+                                                                         Ro: sensor resistance at 1000ppm of
+                                                                             H2 in the clean air.
+
+                                                                         Rs:sensor resistance at various
+                                                                             concentrations of gases.
+
+                     H2                                            ppm
+                     LPG
+                     CH4                                          10000
+                     CO
+                     alcohol
+                     Air
+
+0.1                                   1000
+
+     100
+
+                                  MQ-5        Fig.4               Fig.4 is shows the typical dependence of
+                                                                  the MQ-5 on temperature and humidity.
+Rs/Ro          1.5                                         33%RH
+               1.4                                         85%RH  Ro: sensor resistance at 1000ppm of H2 in air at
+               1.3                                                33%RH and 20 degree.
+               1.2                                                Rs: sensor resistance at different temperatures
+               1.1                                                and humidities.
+
+                  1
+               0.9
+               0.8
+               0.7
+               0.6
+               0.5
+
+          -10        0        10  20    Temp  30     40    50
+
+SENSITVITY ADJUSTMENT
+        Resistance value of MQ-5 is difference to various kinds and various concentration gases. So, When using
+
+this components, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for
+1000ppm H2 or LPG concentration in air and use value of Load resistance ( RL) about 20 KΩ(10KΩ to 47KΩ).
+
+        When accurately measuring, the proper alarm point for the gas detector should be determined after
+considering the temperature and humidity influence.
+
+TEL: 86-371- 67169070 67169080 FAX: 86-371-67169090                      E-mail: sales@hwsensor.com
+

Datasheets/MQ6 - Sparkfun.pdf

@@ -0,0 +1,149 @@
+HANWEI SENSORS                                 MQ-6                            www.hwsensor.com
+
+TECHNICAL DATA                                                              MQ-6 GAS SENSOR
+
+FEATURES
+
+    * High sensitivity to LPG, iso-butane, propane
+
+    * Small sensitivity to alcohol, smoke.
+
+    * Fast response . * Stable and long life * Simple drive circuit
+
+APPLICATION
+
+They are used in gas leakage detecting equipments in family and industry, are suitable for detecting of
+
+LPG, iso-butane, propane, LNG, avoid the noise of alcohol and cooking fumes and cigarette smoke.
+
+SPECIFICATIONS
+
+    A. Standard work condition
+
+Symbol               Parameter name                       Technical condition   Remarks
+                                                                 5V±0.1        AC OR DC
+Vc                   Circuit voltage                             5V±0.1        ACOR DC
+                                                                  20KΩ
+VH                   Heating voltage                                           Room Tem
+                                                                 33Ω±5%
+PL                   Load resistance
+                                                            less than 750mw
+RH                   Heater resistance
+
+PH                   Heating consumption
+
+    B. Environment condition
+
+Symbol               Parameter name                       Technical condition                Remarks
+   Tao                Using Tem                             -10℃-50℃
+   Tas                Storage Tem                           -20℃-70℃
+
+RH                   Related humidity                     less than 95%Rh
+
+O2                   Oxygen concentration      21%(standard condition)Oxygen   minimum value is
+
+                                               concentration can affect sensitivity over 2%
+
+C. Sensitivity characteristic
+
+   Symbol             Parameter name                      Technical parameter           Remarks
+      Rs             Sensing Resistance                       10KΩ- 60KΩ       Detecting concentration
+                                                                               scope：
+     α                                                    (1000ppm LPG )       200-10000ppm
+ (1000ppm/
+4000ppm LPG)         Concentration slope rate             ≤0.6                 LPG , iso-butane,
+Standard                                                                       propane,
+detecting            Temp: 20℃±2℃ Vc:5V±0.1                                    LNG
+condition            Humidity: 65%±5% Vh: 5V±0.1
+
+Preheat time                                Over 24 hour
+
+D. Strucyure and configuration, basic measuring circuit
+
+            Parts    Materials                                                 Fig.2
+1 Gas sensing        SnO2
+
+           layer     Au
+2 Electrode          Pt
+3 Electrode line     Ni-Cr alloy
+4 Heater coil        Al2O3
+5 Tubular ceramic    Stainless steel gauze
+6 Anti-explosion     (SUS316 100-mesh)
+                     Copper plating Ni
+      network        Bakelite
+7 Clamp ring         Copper plating Ni
+8 Resin base
+9 Tube Pin
+
+Configuration A                                Fig. 1
+
+                                                           Configuration B
+
+TEL:86-371-67169080  FAX: 86-A3向71-67169090                                    E-mail:sales@Ah向wsensor.com
+HANWEI SENSORS                                          MQ-6                www.hwsensor.com
+
+   Structure and configuration of MQ-6 gas sensor is shown as Fig. 1 (Configuration A or B), sensor composed by
+micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a
+crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of
+sensitive components. The enveloped MQ-6 have 6 pin ,4 of them are used to fetch signals, and other 2 are used
+for providing heating current.
+
+        Electric parameter measurement circuit is shown as Fig.2
+
+       E. Sensitivity characteristic curve
+
+               Fig.2 sensitivity characteristics of the MQ-6
+
+10                                    MQ-6
+
+Rs/Ro  1                                                                    Fig.3 is shows the typical
+                                                                            sensitivity characteristics of
+
+                                                                            the MQ-6 for several gases.
+
+                                                                                in their: Temp: 20℃、
+                                                                                Humidity: 65%、
+                                                                                O2 concentration 21%
+                                                                                RL=20kΩ
+
+                                                                            Ro: sensor resistance at 1000ppm of
+                                                                                LPG in the clean air.
+
+                                                                            Rs:sensor resistance at various
+                                                                                concentrations of gases.
+
+                     LPG                                              ppm
+                     H2
+                     CH4                                             10000
+                     CO
+                     Alcohol
+                     Air
+
+0.1                                   1000
+    100
+
+Rs/Ro          1.4                MQ-6                        33%RH  Fig.4 is shows the typical dependence of
+               1.3                                            85%RH  the MQ-6 on temperature and humidity.
+               1.2                               Fig.4
+               1.1                                                   Ro: sensor resistance at 1000ppm of LPG in air
+                                                                           at 33%RH and 20 degree.
+                  1
+               0.9                                                   Rs: sensor resistance at 1000ppm of LPG in air
+               0.8                                                         at different temperatures and humidities.
+               0.7
+               0.6
+               0.5
+
+          -10        0        10  20  Temp  30          40    50
+
+SENSITVITY ADJUSTMENT
+        Resistance value of MQ-6 is difference to various kinds and various concentration gases. So, When using
+
+this components, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for
+1000ppm of LPG concentration in air and use value of Load resistance ( RL) about 20KΩ(10KΩ to 47KΩ).
+
+        When accurately measuring, the proper alarm point for the gas detector should be determined after
+considering the temperature and humidity influence.
+
+TEL:86-371-67169080               FAX: 86-371-67169090                      E-mail:sales@hwsensor.com
+

Datasheets/MQ7 - Sparkfun.pdf

@@ -0,0 +1,191 @@
+HANWEI ELECTRONICS CO ., LTD                MQ –7                 http://www.hwsensor.com
+
+TECHNICAL DATA                                             MQ-7 GAS SENSOR
+
+FEATURES
+
+        * High sensitivity to carbon monoxide
+
+        * Stable and long life
+
+APPLICATION
+
+        They are used in gas detecting equipment for carbon monoxide(CO) in family and
+
+industry or car.
+
+SPECIFICATIONS
+
+        A. Standard work condition
+
+Symbol  Parameter name                Technical condition         Remark
+Vc      circuit voltage               5V±0.1                      Ac or Dc
+VH (H)  Heating voltage (high)        5V±0.1                      Ac or Dc
+VH (L)  Heating voltage (low)         1.4V±0.1                    Ac or Dc
+RL      Load resistance
+                                      Can adjust
+
+RH      Heating resistance            33Ω±5%                      Room temperature
+TH (H)  Heating time (high)           60±1 seconds
+TH (L)  Heating time (low)            90±1 seconds
+PH      Heating consumption           About 350mW
+
+b. Environment conditions
+
+Symbol  Parameters                  Technical conditions          Remark
+Tao     Using temperature           -20℃-50℃                      Advice using scope
+Tas     Storage temperature         -20℃-50℃                      Minimum value is over 2%
+RH      Relative humidity
+O2      Oxygen concentration        Less than 95%RH
+                                    21%(stand condition)
+                                    the oxygen concentration can
+                                    affect the sensitivity
+                                    characteristic
+
+c. Sensitivity characteristic
+
+symbol            Parameters                Technical parameters Remark
+Rs
+                  Surface resistance                              In 100ppm
+а(300/100ppm)
+Standard working  Of sensitive body                2-20k          Carbon Monoxide
+condition
+Preheat time      Concentration slope rate     Less than 0.5      Rs (300ppm)/Rs(100ppm)
+
+                  Temperature -20℃±2℃ relative humidity 65%±5% RL:10KΩ±5%
+
+                  Vc:5V±0.1V VH:5V±0.1V VH:1.4V±0.1V
+
+                  No less than 48 hours Detecting range:
+
+                                               20ppm-2000ppm carbon monoxide
+
+ D. Structure and configuration, basic measuring circuit
+    Structure and configuration of MQ-7 gas sensor is shown as Fig. 1 (Configuration A or B),
+
+sensor composed by micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring
+electrode and heater are fixed into a crust made by plastic and stainless steel net. The heater
+provides necessary work conditions for work of sensitive components. The enveloped MQ-7 have
+
+TEL:86-371-67169070 67169080          FAX:86-371-67169090         Email: sales@hwsensor.com
+HANWEI ELECTRONICS CO ., LTD                                   MQ –7     http://www.hwsensor.com
+
+6 pin ,4 of them are used to fetch signals, and other 2 are used for providing heating current.
+
+                                                                Parts    Materials
+                                                    1 Gas sensing        SnO2
+
+                                                               layer     Au
+                                                    2 Electrode          Pt
+                                                    3 Electrode line     Ni-Cr alloy
+                                                    4 Heater coil        Al2O3
+                                                    5 Tubular ceramic    Stainless steel gauze
+                                                    6 Anti-explosion     (SUS316 100-mesh)
+                                                                         Copper plating Ni
+                                                          network        Bakelite
+                                                    7 Clamp ring         Copper plating Ni
+                                                    8 Resin base
+                                                    9 Tube Pin
+
+                                                    Fig.1
+
+                                A
+
+                                A
+                                          A向
+
+VH                              Heating voltage 5v (High) 60s  Standard circuit:
+                                                               As shown in Fig 2, standard measuring circuit of
+                                          VRL                  MQ-7 sensitive components consists of 2 parts. one
+                                                               is heating circuit having time control function (the
+                                                  RL           high voltage and the low voltage work
+                                Vc                             circularly ). The second is the signal output circuit,
+                                                               it can accurately respond changes of surface
+                                            Fig.2              resistance of the sensor.
+
+Heating voltage 1.4v (Low) 90s
+
+Electric parameter measurement circuit is shown as Fig.2
+ E. Sensitivity characteristic curve
+
+100                             MQ-7
+
+10                                                                       Fig.3 is shows the typical
+                                                                         sensitivity characteristics of
+Rs/Ro1                                                                   the MQ-7 for several gases.
+
+ 0.1       CO                                                  ppm           in their: Temp: 20℃、
+           H2                                                                Humidity: 65%、
+0.01       LPG                                1000             10000         O2 concentration 21%
+       10  CH4                                                               RL=10kΩ
+           Alcohol                                                       Ro: sensor resistance at 100ppm
+           air
+                                                                                CO in the clean air.
+                   100                                                   Rs: sensor resistance at various
+
+        Fig.3 sensitivity characteristics of the MQ-7                        concentrations of gases.
+
+TEL:86-371-67169070 67169080                        FAX:86-371-67169090        Email: sales@hwsensor.com
+HANWEI ELECTRONICS CO ., LTD                                MQ –7                    http://www.hwsensor.com
+
+            1.5                          MQ-7                                Fig.4 is shows the typical
+            1.4                                                              dependence of the MQ-7 on
+            1.3                                    33%RH        Fig.4        temperature and humidity.
+                                                   85%RH
+            1.2                                                              Ro: sensor resistance at 100ppm CO in
+Rs/Ro       1.1                                                              air at 33%RH and 20degree.
+                                                                             Rs: sensor resistance at 100ppm CO at
+               1                                                       Temp  different temperatures and humidities.
+            0.9
+            0.8
+
+            0.7
+            0.6
+            0.5
+
+       -10        0  10                  20    30           40     50
+
+OPERATION PRINCIPLE
+. The surface resistance of the sensor Rs is obtained through effected voltage signal output of the
+load resistance RL which series-wound. The relationship between them is described:
+
+                                  Rs\RL = (Vc-VRL) / VRL
+Fig. 5 shows alterable situation of RL signal output measured by using Fig. 2 circuit output
+
+                                               In 100ppmCO                   In air
+
+VH5v                             In air
+1.4v              60s 90s
+
+Signal
+
+                                                   Fig.5
+
+signal when the sensor is shifted from clean air to carbon monoxide (CO) , output signal
+measurement is made within one or two complete heating period (2.5 minute from high voltage
+to low voltage ).
+
+      Sensitive layer of MQ-7 gas sensitive components is made of SnO2 with stability, So, it has
+excellent long term stability. Its service life can reach 5 years under using condition.
+SENSITVITY ADJUSTMENT
+
+      Resistance value of MQ-7 is difference to various kinds and various concentration gases. So, When
+using this components, sensitivity adjustment is very necessary. we recommend that you calibrate the
+detector for 200ppm CO in air and use value of Load resistance that( RL) about 10 KΩ(5KΩ to 47 KΩ).
+
+      When accurately measuring, the proper alarm point for the gas detector should be determined after
+ considering the temperature and humidity influence. The sensitivity adjusting program:
+
+      a. Connect the sensor to the application circuit.
+      b. Turn on the power, keep preheating through electricity over 48 hours.
+      c. Adjust the load resistance RL until you get a signal value which is respond to a certain
+
+         carbon monoxide concentration at the end point of 90 seconds.
+      d. Adjust the another load resistance RL until you get a signal value which is respond to a CO
+
+         concentration at the end point of 60 seconds .
+
+                          Supplying special IC solutions, More detailed technical information, please contact us.
+
+       TEL:86-371-67169070 67169080            FAX:86-371-67169090           Email: sales@hwsensor.com
+

Datasheets/MQ8 - Sparkfun.pdf

@@ -0,0 +1,150 @@
+HANWEI ELETRONICS CO.,LTD                               MQ-8                           http://www.hwsensor.com
+
+TECHNICAL DATA                                                           MQ-8 GAS SENSOR
+
+FEATURES
+
+    * High sensitivity to Hydrogen (H2)
+    * Small sensitivity to alcohol, LPG,cooking fumes
+
+    * Stable and long life
+
+APPLICATION
+
+They are used in gas leakage detecting equipments in family and industry, are suitable for
+
+detecting of Hydrogen (H2), avoid the noise of alcohol and cooking fumes, LPG,CO.
+
+SPECIFICATIONS
+
+    A. Standard work condition
+
+Symbol             Parameter name                       Technical condition                           Remarks
+
+Vc                 Circuit voltage                            5V±0.1                   AC OR DC
+
+VH                 Heating voltage                          5V±0.1                     ACOR DC
+                                                              10KΩ                     Room Tem
+PL                 Load resistance                          31±5%
+                                                        less than800mW
+RH                 Heater resistance
+
+PH                 Heating consumption
+
+    B. Environment condition
+
+Symbol             Parameter name                       Technical condition                           Remarks
+   Tao              Using Tem                              -10℃-50℃
+
+Tas                Storage Tem                          -20℃-70℃
+
+RH                 Related humidity                     less than 95%Rh
+
+O2                 Oxygen concentration                 21%(standard condition)Oxygen  minimum value is
+
+                                                        concentration can affect sensitivity over 2%
+
+C. Sensitivity characteristic
+
+   Symbol           Parameter name                      Technical parameter                     Ramark 2
+      Rs           Sensing Resistance                       10KΩ- 60KΩ                 Detecting concentration
+                                                                                       scope：
+      α                                                 (1000ppm H2)                   100-10000ppm
+ (1000ppm/
+500ppmH2)                                                     ≤0.6                     Hydrogen (H2)
+Standard
+detecting          Concentration slope rate
+condition
+                   Temp: 20℃±2℃ Vc:5V±0.1
+                   Humidity: 65%±5% Vh: 5V±0.1
+
+Preheat time                              Over 24 hour
+
+D. Structure and configuration, basic measuring circuit
+
+            Parts  Materials                                                           Fig.2
+1 Gas sensing      SnO2
+
+          layer    Au
+2 Electrode        Pt
+3 Electrode line   Ni-Cr alloy
+4 Heater coil      Al2O3
+5 Tubular ceramic  Stainless steel gauze
+6 Anti-explosion   (SUS316 100-mesh)
+                   Copper plating Ni
+      network      Bakelite
+7 Clamp ring       Copper plating Ni
+8 Resin base
+9 Tube Pin
+
+Configuration A                              Fig. 1
+
+                                                        Configuration B
+
+                                                    A向                                              A向
+TEL: 86-371- 67169070 67169080 FAX: 86-371-67169090
+                                                                                       E-mail: sales@hwsensor.com
+HANWEI ELETRONICS CO.,LTD                                    MQ-8         http://www.hwsensor.com
+
+   Structure and configuration of MQ-8 gas sensor is shown as Fig. 1 (Configuration A or B), sensor composed by
+micro AL2O3 ceramic tube, Tin Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a
+crust made by plastic and stainless steel net. The heater provides necessary work conditions for work of
+sensitive components. The enveloped MQ-8 have 6 pin ,4 of them are used to fetch signals, and other 2 are used
+for providing heating current.
+
+        Electric parameter measurement circuit is shown as Fig.2
+
+       E. Sensitivity characteristic curve
+
+100                                   MQ-8
+
+       10                                                                                Fig.3 is shows the typical
+                                                                                         sensitivity characteristics of
+    1Rs/Ro               H2                                                              the MQ-8 for several gases.
+                         LPG
+ 0.1                     CH4                                                                    in their: Temp: 20℃、
+                         CO                                                                     Humidity: 65%、
+0.01                     alcohol                                                                O2 concentration 21%
+      100                air                                                                    RL=10kΩ
+                                                                                            Ro: sensor resistance at 1000ppm
+                                      1000                                                  H2 in the clean air.
+                                                                                            Rs:sensor resistance at various
+                                                                                                concentrations of gases.
+
+                                                                            ppm
+                                                                       10000
+
+              Fig.2 sensitivity characteristics of the MQ-8
+
+       Rs/Ro       1.3                MQ-8                         33%RH  Fig.4 is shows the typical dependence of
+                   1.2                                             85%RH
+                   1.1                        Fig.4                       the MQ-8 on temperature and humidity.
+
+                      1                                                   Ro: sensor resistance at 1000ppm of H2 in air at
+                                                                                33%RH and 20 degree.
+                   0.9
+                   0.8                                                    Rs: sensor resistance at 1000ppm of H2 in air
+                   0.7                                                           at different temperatures and humidities.
+                   0.6
+                   0.5
+                   0.4
+
+                   0.3
+                   0.2
+                   0.1
+
+                      0
+
+              -10        0        10  20  Temp  30           40    50
+
+SENSITVITY ADJUSTMENT
+        Resistance value of MQ-8 is difference to various kinds and various concentration gases. So,When using
+
+this components, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for
+1000ppm H2 concentration in air and use value of Load resistance ( RL) about 10 KΩ(5KΩ to 33 KΩ).
+
+        When accurately measuring, the proper alarm point for the gas detector should be determined after
+considering the temperature and humidity influence.
+
+TEL: 86-371- 67169070 67169080 FAX: 86-371-67169090                       E-mail: sales@hwsensor.com
+

Datasheets/MQ9 - Hanwei.pdf

@@ -0,0 +1,169 @@
+Henan Hanwei Electronics Co., Ltd                                                   www.hwsensor.com
+
+           MQ-9 Semiconductor Sensor for CO/Combustible Gas
+
+    Sensitive material of MQ-9 gas sensor is SnO2, which with lower conductivity in clean air. It make
+detection by method of cycle high and low temperature, and detect CO when low temperature (heated
+by 1.5V). The sensor’s conductivity is more higher along with the gas concentration rising. When high
+temperature (heated by 5.0V), it detects Methane, Propane etc combustible gas and cleans the other
+gases adsorbed under low temperature. Please use simple electrocircuit, Convert change of conductivity
+to correspond output signal of gas concentration.
+
+    MQ-9 gas sensor has high sensitity to Carbon Monoxide, Methane and LPG. The sensor could be
+used to detect different gases contains CO and combustible gases, it is with low cost and suitable for
+different application.
+
+Character                                              Configuration
+
+* Good sensitivity to CO/Combustible gas
+* High sensitivity to Methane, Propane and CO
+* Long life and low cost
+* Simple drive circuit
+
+Application
+
+* Domestic gas leakage detector
+* Industrial gas detector
+* Portable gas detector
+Technical Data
+
+                                                                   Basic test loop
+
+         Model No.                                   MQ-9          V                                       VR
+       Sensor Type                             Semiconductor
+Standard Encapsulation                                                                               RL
+      Detection Gas                                 Bakelite           VH
+      Concentration                     CO and combustible gas
+                                                                   GND
+           Loop Voltage Vc                    10-1000ppm CO
+                                    100-10000ppm combustible gas   The above is basic test circuit of the
+Circuit      Heater Voltage VH                                     sensor. The sensor need to be put 2
+                                                   ≤10V DC         voltage, heater voltage（VH） and
+             Heater Time    TL         5.0V±0.2V ACorDC（High）      test voltage（VC）. VH used to
+                                      1.5V±0.1V ACorDC（Low）        supply certified working temperature
+           Load Resistance RL       60±1S（High）90±1S（Low）          to the sensor, while VC used to
+                                                                   detect voltage (VRL) on load
+           Heater Resistance RH                   Adjustable       resistance（RL）whom is in series
+                                         31Ω±3Ω（Room Tem.）         with sensor. The sensor has light
+                 Heater     PH                                     polarity, Vc need DC power. VC and
+             consumption                           ≤350mW          VH could use same power circuit
+                                                                   with precondition to assure
+Character     Sensing       Rs         2KΩ-20KΩ(in 100ppm CO )     performance of sensor. In order to
+             Resistance                                            make the sensor with better
+                                      Rs(in air)/Rs(100ppm CO)≥5
+             Sensitivity    S            ≤0.6(R300ppm/R100ppm CO)
+                                          20℃±2℃; 65%±5%RH
+             Slope          α
+                                    Vc:5.0V±0.1V;
+             Tem. Humidity          VH（High）: 5.0V±0.1V；
+                                    VH（Low）: 1.5V±0.1V
+Condition    Standard test circuit
+                                               Over 48 hours
+             Preheat time
+
+            performance, suitable RL value is needed:                 Email: sales@hwsensor.com
+Power of Sensitivity body(Ps): Ps=Vc2×Rs/(Rs+RL)2
+Tel: 86-371-67169070/80 Fax: 86-371-67169090
+Henan Hanwei Electronics Co., Ltd                                                      www.hwsensor.com
+                                                         Influence of Temperature/Humidity
+Resistance of sensor(Rs): Rs=(Vc/VRL-1)×RL
+
+ Sensitivity Characteristics
+
+Fig.1 shows the typical sensitivity characteristics of        Fig.2 shows the typical temperature and humidity
+the MQ-9, ordinate means resistance ratio of the sensor       characteristics. Ordinate means resistance ratio
+                                                          of the sensor (Rs/Ro), Rs means resistance of sensor
+(Rs/Ro), abscissa is concentration of gases. Rs means    in 1000ppm Propane under different tem. and humidity.
+                                                           Ro means resistance of the sensor in environment of
+resistance in different gases, Ro means resistance of     1000ppm Propane, 20℃/65%RH
+sensor in 1000ppm LPG. All test are under standard
+test conditions.
+
+Structure and configuration
+
+Structure and configuration of MQ-9 gas sensor is shown as Fig. 3, sensor composed by micro AL2O3 ceramic tube, Tin
+Dioxide (SnO2) sensitive layer, measuring electrode and heater are fixed into a crust made by plastic and stainless steel
+net. The heater provides necessary work conditions for work of sensitive components. The enveloped MQ-7 have 6 pin, 4
+of them are used to fetch signals, and other 2 are used for providing heating current.
+
+Tel: 86-371-67169070/80 Fax: 86-371-67169090             Email: sales@hwsensor.com
+Henan Hanwei Electronics Co., Ltd                                              www.hwsensor.com
+
+Notification
+
+1 Following conditions must be prohibited
+1.1 Exposed to organic silicon steam
+
+      Organic silicon steam cause sensors invalid, sensors must be avoid exposing to silicon bond,
+fixature, silicon latex, putty or plastic contain silicon environment
+
+1.2 High Corrosive gas
+
+      If the sensors exposed to high concentration corrosive gas (such as H2Sz, SOX，Cl2，HCl etc), it will
+not only result in corrosion of sensors structure, also it cause sincere sensitivity attenuation.
+
+1.3 Alkali, Alkali metals salt, halogen pollution
+
+      The sensors performance will be changed badly if sensors be sprayed polluted by alkali metals salt
+especially brine, or be exposed to halogen such as fluorin.
+
+1.4 Touch water
+      Sensitivity of the sensors will be reduced when spattered or dipped in water.
+
+1.5 Freezing
+      Do avoid icing on sensor’surface, otherwise sensor would lose sensitivity.
+
+1.6 Applied voltage higher
+
+    Applied voltage on sensor should not be higher than stipulated value, otherwise it cause down-line or
+heater damaged, and bring on sensors’ sensitivity characteristic changed badly.
+
+1.7 Voltage on wrong pins
+    For 6 pins sensor, if apply voltage on 1、3 pins or 4、6 pins, it
+
+will make lead broken, and without signal when apply on 2、4 pins
+
+2 Following conditions must be avoided
+2.1 Water Condensation
+
+    Indoor conditions, slight water condensation will effect sensors performance lightly. However, if water
+condensation on sensors surface and keep a certain period, sensor’ sensitivity will be decreased.
+
+2.2 Used in high gas concentration
+      No matter the sensor is electrified or not, if long time placed in high gas concentration, if will affect
+
+sensors characteristic.
+
+2.3 Long time storage
+      The sensors resistance produce reversible drift if it’s stored for long time without electrify, this drift is
+
+related with storage conditions. Sensors should be stored in airproof without silicon gel bag with clean air.
+For the sensors with long time storage but no electrify, they need long aging time for stbility before using.
+
+2.4 Long time exposed to adverse environment
+    No matter the sensors electrified or not, if exposed to adverse environment for long time, such as
+
+high humidity, high temperature, or high pollution etc, it will effect the sensors performance badly.
+
+2.5 Vibration
+      Continual vibration will result in sensors down-lead response then repture. In transportation or
+
+assembling line, pneumatic screwdriver/ultrasonic welding machine can lead this vibration.
+
+2.6 Concussion
+   If sensors meet strong concussion, it may lead its lead wire disconnected.
+
+2.7 Usage
+   For sensor, handmade welding is optimal way. If use wave crest welding should meet the following
+
+conditions:
+   2.7.1 Soldering flux: Rosin soldering flux contains least chlorine
+   2.7.2 Speed: 1-2 Meter/ Minute
+   2.7.3 Warm-up temperature：100±20℃
+   2.7.4 Welding temperature：250±10℃
+
+   2.7.5 1 time pass wave crest welding machine
+If disobey the above using terms, sensors sensitivity will be reduced.
+
+Tel: 86-371-67169070/80 Fax: 86-371-67169090                                   Email: sales@hwsensor.com
+

Internal_design_documents/Datasheet Graphs.docx

@@ -0,0 +1,25 @@
+MQ2
+
+MQ3
+
+MQ4
+
+MQ5
+
+MQ6
+
+MQ7
+
+MQ8
+
+MQ9
+
+MQ131
+
+MQ135
+
+
+MQ303A
+
+MQ309A
+

Internal_design_documents/Experiments/.ipynb_checkpoints/LinearRegression-checkpoint.ipynb

@@ -0,0 +1,6 @@
+{
+ "cells": [],
+ "metadata": {},
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

README.md

@@ -1,143 +1,40 @@
-<!-- PROJECT SHIELDS -->
-<!--
-*** I'm using markdown "reference style" links for readability.
-*** Reference links are enclosed in brackets [ ] instead of parentheses ( ).
-*** See the bottom of this document for the declaration of the reference variables
-*** for contributors-url, forks-url, etc. This is an optional, concise syntax you may use.
-*** https://www.markdownguide.org/basic-syntax/#reference-style-links
--->
-[![DOI](https://zenodo.org/badge/170540207.svg)](https://zenodo.org/badge/latestdoi/170540207)
-![Build Status][build-url]
-[![Contributors][contributors-shield]][contributors-url]
-[![Forks][forks-shield]][forks-url]
-[![Stargazers][stars-shield]][stars-url]
-[![Issues][issues-shield]][issues-url]
-[![MIT License][license-shield]][license-url]
-[![LinkedIn][linkedin-shield]][linkedin-url]
+[![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.3384299.svg)](https://doi.org/10.5281/zenodo.3384299)
+![Build Status](https://travis-ci.org/dwyl/esta.svg?branch=master)
 
 # MQSensorsLib
 
-We present a unified library for MQ sensors, this library allows to read MQ signals easily from Arduino, Genuino, ESP8266, ESP-32 boards whose references are MQ2, MQ3, MQ4, MQ5, MQ6, MQ7, MQ8, MQ9, MQ131, MQ135, MQ303A, MQ309A.
-
-<!-- TABLE OF CONTENTS -->
-## Table of Contents
-
-* [Getting Started](#Getting-Started)
-* [Wiring](#Wiring)
-  * [Sensor](#Sensor)
-  * [Arduino](#Arduino)
-  * [ESP8266 or ESP-32](#ESP8266-ESP32)
-* [User Manual](#Manuals)
-* [Sensor manufacturers](#Sensor-manufacturers)
-* [Contributing](#Contributing)
-* [Authors](#Authors)
-* [Be a sponsor 💖](#Sponsor)
+This is a unified library to use sensors MQ: 2, 3, 4, 5, 6, 7, 8, 9, 131, 135, 303A and 309A.
 
 ## Getting Started
 
 ```
-//Include the library
-#include <MQUnifiedsensor.h>
-/************************Hardware Related Macros************************************/
-#define         Board                   ("Arduino UNO")
-#define         Pin                     (A4)  //Analog input 4 of your arduino
-/***********************Software Related Macros************************************/
-#define         Type                    ("MQ-4") //MQ4
-#define         Voltage_Resolution      (5)
-#define         ADC_Bit_Resolution      (10) // For arduino UNO/MEGA/NANO
-#define         RatioMQ4CleanAir        (4.4) //RS / R0 = 60 ppm 
-/*****************************Globals***********************************************/
-//Declare Sensor
-MQUnifiedsensor MQ4(Board, Voltage_Resolution, ADC_Bit_Resolution, Pin, Type);
-// Setup
-MQ4.setRegressionMethod("Exponential"); //_PPM =  a*ratio^b
-MQ4.setA(1012.7); MQ4.setB(-2.786); // Configure the equation to to calculate CH4 concentration
-MQ4.setR0(3.86018237); // Value getted on calibration
-// Loop
-MQ4.init();
-MQ4.update();
+MQUnifiedsensor MQ4(pin, 4); //Example if sensor is MQ4, type = 4
 float ppmCH4 = MQ4.readSensor();
 ```
 
-## Wiring
-### Sensor
-#### Important points:
-##### Points you should identify
-* VCC -> 5V Power supply (+) wire
-* GND -> GND Ground (-) wire
-* AO -> Analog Output of the sensor
-##### Data of board that you should have
-* RL Value in KOhms
-##### Graph
-![Wiring_MQSensor](https://raw.githubusercontent.com/miguel5612/MQSensorsLib_Docs/master/static/img/Points_explanation.jpeg)
-#### RS/R0 value (From datasheet of your sensor)
-* RS/R0 (Clean air - English) -> (Aire puro - Spanish)
-* **Note**: RS/R0 is equal to Ratio variable on the program
-![Graph from datasheet](https://raw.githubusercontent.com/miguel5612/MQSensorsLib_Docs/master/static/img/Graph_Explanation.jpeg)
-### Arduino
-![Arduino_Wiring_MQSensor](https://raw.githubusercontent.com/miguel5612/MQSensorsLib_Docs/master/static/img/MQ_Arduino.PNG)
-#### MQ-7 / MQ-309A
-** Note ** [issue](https://github.com/miguel5612/MQSensorsLib/issues/26): MQ-7 and MQ-309 needs two different voltages for heater, they can be supplied by PWM and DC Signal controlled by your controller, another option is to use two different power sources, you should use the best option for you, next i will show the PWM option and on the examples this will be the way .
-![MQ-7_MQ-309](https://raw.githubusercontent.com/miguel5612/MQSensorsLib_Docs/master/static/img/MQ-309_MQ-7.PNG)
-### ESP8266-ESP32
-![ESP8266_Wiring_MQSensor](https://raw.githubusercontent.com/miguel5612/MQSensorsLib_Docs/master/static/img/MQ_ESP8266.PNG)
-
-### ESP32 WROOM 32D
-The ESP32 WROOM 32D does not need an external power supply. A0 goes to PIN36, Vcc to 3v3 and GND to any GND port on the board. Check the **ESP2/ESP32_WROOM_32** folder to fixing the measuring issue when connecting to wifi.
-
-### Manuals
-#### User Manual (v1.0) 12.2019
-[Manual](https://drive.google.com/open?id=1BAFInlvqKR7h81zETtjz4_RC2EssvFWX)
-#### User Manual (v2.0) 04.2020
-[Manual](https://github.com/miguel5612/MQSensorsLib_Docs/blob/master/Docs/MQSensorLib_2.0.pdf)
-
-### Serial debug (optional)
-If your sensor is an **MQ2** (Same for others sensors):
-* To enable on setup wrote
-```
-MQ2.serialDebug(true); 
-```
-* And on Loop Wrote
-```
-MQ2.serialDebug(); 
-```
-* Result:
-
-![Serial debug output](https://github.com/miguel5612/MQSensorsLib_Docs/blob/master/static/img/Serial_Mon_Explanation.jpeg?raw=true)
-
-**Note**: 
-* ![#c5f015](https://placehold.it/15/c5f015/000000?text=+) `Yellow -> Calibration status.`
-* ![#008000](https://placehold.it/15/008000/000000?text=+) `Green -> Hardware and software characteristics.`
-* ![#f03c15](https://placehold.it/15/f03c15/000000?text=+) `Red -> Headers of the library calculations.`
-* Only valid for **1** gas sensor readings.
-
-**Usage**
-* Quick troubleshooting, since it shows everything the library does and the results of the calculations in each function.
-
 ### Prerequisites
 
 You'll need Arduino desktop app 1.8.9 or later.
 
-### Sensor manufacturers:
+### Sensor manufacture:
 | Sensor | Manufacture | URL Datasheet |
 |----------|----------|----------|
-| MQ-2 | HANWEI Electronics| [datasheet](https://www.pololu.com/file/0J309/MQ2.pdf) |
-| MQ-3 | HANWEI Electronics | [datasheet](https://www.sparkfun.com/datasheets/Sensors/MQ-3.pdf) |
-| MQ-4 | HANWEI Electronics | [datasheet](https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-4.pdf) |
-| MQ-5 | HANWEI Electronics | [datasheet](https://www.parallax.com/sites/default/files/downloads/605-00009-MQ-5-Datasheet.pdf) |
-| MQ-6 | HANWEI Electronics | [datasheet](https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-6.pdf) |
-| MQ-7 | HANWEI Electronics | [datasheet](https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-7.pdf) |
-| MQ-8 | HANWEI Electronics | [datasheet](https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Biometric/MQ-8.pdf) |
-| MQ-9 | HANWEI Electronics | [datasheet](http://www.haoyuelectronics.com/Attachment/MQ-9/MQ9.pdf) |
-| MQ-131 | HANWEI Electronics | [datasheet](http://www.sensorsportal.com/DOWNLOADS/MQ131.pdf) |
+| MQ-2 | Pololulu| [datasheet](https://www.pololu.com/file/0J309/MQ2.pdf) |
+| MQ-3 | Sparkfun | [datasheet](https://www.sparkfun.com/datasheets/Sensors/MQ-3.pdf) |
+| MQ-4 | Sparkfun | [datasheet](https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-4.pdf) |
+| MQ-5 | parallax | [datasheet](https://www.parallax.com/sites/default/files/downloads/605-00009-MQ-5-Datasheet.pdf) |
+| MQ-6 | Sparkfun | [datasheet](https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-6.pdf) |
+| MQ-7 | Sparkfun | [datasheet](https://www.sparkfun.com/datasheets/Sensors/Biometric/MQ-7.pdf) |
+| MQ-8 | Sparkfun | [datasheet](https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Biometric/MQ-8.pdf) |
+| MQ-9 | Haoyuelectronics | [datasheet](http://www.haoyuelectronics.com/Attachment/MQ-9/MQ9.pdf) |
+| MQ-131 | Sensorsportal | [datasheet](http://www.sensorsportal.com/DOWNLOADS/MQ131.pdf) |
 | MQ-135 | HANWEI Electronics | [datasheet](https://www.electronicoscaldas.com/datasheet/MQ-135_Hanwei.pdf) |
-| MQ-136 | HANWEI Electronics | [datasheet](https://github.com/miguel5612/MQSensorsLib_Docs/blob/master/Datasheets/MQ136%20-%20Hanwei.pdf) |
 | MQ-303A | HANWEI Electronics | [datasheet](http://www.kosmodrom.com.ua/pdf/MQ303A.pdf) |
 | MQ-309A | HANWEI Electronics | [datasheet](http://www.sensorica.ru/pdf/MQ-309A.pdf) |
 
 ### Info of datasheets 
 
-Review WPDigitalizer [folder](https://github.com/miguel5612/MQSensorsLib_Docs/tree/master/WPDigitalizer) [website](https://automeris.io/WebPlotDigitizer/)
+Review WPDigitalizer [folder](https://github.com/miguel5612/MQSensorsLib/tree/master/WPDigitalizer) [website](https://automeris.io/WebPlotDigitizer/)
 
 ### Installing
 
@@ -170,16 +67,12 @@ Examples/MQ-board.ino
 
 ## Built With
 
-* [Data sheets](https://github.com/miguel5612/MQSensorsLib_Docs/tree/master/Datasheets) - Curves and behavior for each sensor, using logarithmic graphs.
-* [Main purpose](https://github.com/miguel5612/MQSensorsLib_Docs/blob/master/static/img/bg.jpg) - Every sensor has high sensibility for a specific gas or material.
+* [Data sheets](https://github.com/miguel5612/MQSensorsLib/tree/master/Datasheets) - Curves and behavior for each sensor, using logarithmic graphs.
+* [Main purpose](https://github.com/miguel5612/MQSensorsLib/blob/master/static/img/bg.jpg) - Every sensor has high sensibility for a specific gas or material.
 
 ## Contributing
 
-Please read [CONTRIBUTING.md](https://github.com/miguel5612/MQSensorsLib/blob/master/CONTRIBUTING.md) for details on our code of conduct, and the process for submitting pull requests to us.
-
-## Reviewers
-
-* **PhD. Jacipt A Ramón V.** - [*GitHub*]() - [CV](https://scienti.minciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0000512702)
+Please read [CONTRIBUTING.md](https://github.com/miguel5612/MQSensorsLib/blob/NO_Functional/CONTRIBUTING.md) for details on our code of conduct, and the process for submitting pull requests to us.
 
 ## Authors
 
@@ -189,8 +82,8 @@ Please read [CONTRIBUTING.md](https://github.com/miguel5612/MQSensorsLib/blob/ma
 
 ## Collaborators
 
-* **Andres A. Martinez.** - [*Github*](https://github.com/andresmacsi) - [CV](https://www.linkedin.com/in/andr%C3%A9s-acevedo-mart%C3%ADnez-73ab35185/?originalSubdomain=co)
-* **Juan A. Rodríguez.** - [*Github*](https://github.com/Obiot24) - [CV]()
+* **Andres A. Martinez.** 
+* **Juan A. Rodríguez.** - [*Github*](https://github.com/Obiot24)
 * **Mario A. Rodríguez O.** - [*GitHub*](https://github.com/MarioAndresR) - [CV](https://scienti.colciencias.gov.co/cvlac/visualizador/generarCurriculoCv.do?cod_rh=0000111304)
 
 See also the list of [contributors](https://github.com/miguel5612/MQSensorsLib/contributors) who participated in this project.
@@ -201,67 +94,14 @@ This project is licensed under the MIT License - see the [LICENSE.md](LICENSE.md
 
 ## Cite as
 
-* Plain text: Califa Urquiza, Miguel Angel, Contreras Contreras, Ghiordy, & Carrillo Amado, Yerson Ramiro. (2019, September 3). miguel5612/MQSensorsLib: Arduino Preview V1.03 (Version 1.0.3). Zenodo. http://doi.org/10.5281/zenodo.3384301
-* CSL: {
-  "publisher": "Zenodo", 
-  "DOI": "10.5281/zenodo.3384301", 
-  "title": "miguel5612/MQSensorsLib: Arduino Preview V1.03", 
-  "issued": {
-    "date-parts": [
-      [
-        2019, 
-        9, 
-        3
-      ]
-    ]
-  }, 
-  "abstract": "<p>Publishing on Zenodo platform as software in order to extend its applications for other works allowing to recognize MQSensorLib&#39;s Authors this work into scientific community using Digital Object Identifier System (DOI).</p>", 
-  "author": [
-    {
-      "family": "Califa Urquiza, Miguel Angel"
-    }, 
-    {
-      "family": "Contreras Contreras, Ghiordy"
-    }, 
-    {
-      "family": "Carrillo Amado, Yerson Ramiro"
-    }
-  ], 
-  "version": "1.0.3", 
-  "type": "article", 
-  "id": "3384301"
-}
+* Plain text: Miguel Angel Califa Urquiza. (2019, September 3). Ghiordy/MQSensorsLib: Arduino Preview V1.0.3 (Version 1.0.3). Zenodo. http://doi.org/10.5281/zenodo.3384299
 * BibTeX: 
-@misc{califa_urquiza_miguel_angel_2019_3384301,
-  author       = {Califa Urquiza, Miguel Angel and
-                  Contreras Contreras, Ghiordy and
-                  Carrillo Amado, Yerson Ramiro},
-  title        = {miguel5612/MQSensorsLib: Arduino Preview V1.03},
+@misc{miguel_angel_califa_urquiza_2019_3384299,
+  author       = {Miguel Angel Califa Urquiza},
+  title        = {Ghiordy/MQSensorsLib: Arduino Preview V1.0.3},
   month        = sep,
   year         = 2019,
-  doi          = {10.5281/zenodo.3384301},
-  url          = {https://doi.org/10.5281/zenodo.3384301}
+  doi          = {10.5281/zenodo.3384299},
+  url          = {https://doi.org/10.5281/zenodo.3384299}
 }
 
-
-## Sponsor
-
-* [Paypal](https://www.paypal.com/paypalme/miguel5612)
-
-
-<!-- MARKDOWN LINKS & IMAGES -->
-<!-- https://www.markdownguide.org/basic-syntax/#reference-style-links -->
-[contributors-shield]: https://img.shields.io/github/contributors/miguel5612/MQSensorsLib.svg?style=flat-square
-[contributors-url]: https://github.com/miguel5612/MQSensorsLib/graphs/contributors
-[forks-shield]: https://img.shields.io/github/forks/miguel5612/MQSensorsLib.svg?style=flat-square
-[forks-url]: https://github.com/miguel5612/MQSensorsLib/network/members
-[stars-shield]: https://img.shields.io/github/stars/miguel5612/MQSensorsLib.svg?style=flat-square
-[stars-url]: https://github.com/miguel5612/MQSensorsLib/stargazers
-[issues-shield]: https://img.shields.io/github/issues/miguel5612/MQSensorsLib.svg?style=flat-square
-[issues-url]: https://github.com/miguel5612/MQSensorsLib/issues
-[license-shield]: https://img.shields.io/github/license/miguel5612/MQSensorsLib.svg?style=flat-square
-[license-url]: https://github.com/miguel5612/MQSensorsLib/blob/master/LICENSE.txt
-[linkedin-shield]: https://img.shields.io/badge/-LinkedIn-black.svg?style=flat-square&logo=linkedin&colorB=555
-[build-url]: https://travis-ci.org/dwyl/esta.svg?branch=master
-[linkedin-url]: https://www.linkedin.com/in/miguel5612
-[product-screenshot]: images/screenshot.png

WPDigitalizer/MQ131/CL2.csv

@@ -0,0 +1,5 @@
+4.957713628975931; 5.970352865838375
+9.82303087255475; 3.890451449942809
+19.66936860744601; 2.365919697485761
+49.50200098710442; 0.9908319448927686
+99.17887133636847; 0.49659232145033677

WPDigitalizer/MQ131/NOx.csv

@@ -0,0 +1,5 @@
+5.004690736196025; 8.090958991783829
+9.81247228520288; 5.571857489319305
+19.63847609606165; 3.9994474976109777
+49.85956704514034; 2.8313919957993816
+98.7613064604988; 2.032357010936224

WPDigitalizer/MQ131/O3.csv

@@ -0,0 +1,5 @@
+5.015052099488824; 4.055085354483843
+9.839297042431014; 2.2387211385683425
+19.708460197689764; 1.2189895989248674
+50.120105449151986; 0.49659232145033727
+99.34721307419954; 0.2818382931264458

WPDigitalizer/MQ135/Acetona.csv

@@ -0,0 +1,3 @@
+10.038068731719024; 1.4367778871086752
+100.76282386271518; 0.7437057711666111
+199.67791490816478; 0.5858066785834567

WPDigitalizer/MQ135/Alcohol.csv

@@ -0,0 +1,3 @@
+10; 1.8980643862295867
+100.76282386271518; 0.9276207214357883
+199.67791490816478; 0.7371610501169261

WPDigitalizer/MQ135/CO.csv

@@ -0,0 +1,3 @@
+9.92429510870452; 2.850325339883499
+100.76282386271518; 1.5488850711364055
+199.67791490816478; 1.3446177759671738

WPDigitalizer/MQ135/CO2.csv

@@ -0,0 +1,3 @@
+10; 2.3054935712377356
+100.76282386271518; 1.049816136090719
+198.16625542394166; 0.8052859018667691

WPDigitalizer/MQ135/NH4.csv

@@ -0,0 +1,3 @@
+10; 2.563475521052897
+100.38068731719024; 1
+199.67791490816478; 0.7670732751979543

WPDigitalizer/MQ135/Tolueno.csv

@@ -0,0 +1,3 @@
+10; 1.5420548019516276
+100.38068731719024; 0.8017347542813508
+199.67791490816478; 0.6427786162225773

WPDigitalizer/MQ2/Alcohol.csv

@@ -0,0 +1,9 @@
+202,97159045689085; 2,870821251841819
+493,62843297110385; 2,120486081991352
+789,3018264543583; 1,722949305824931
+1013,5564768245204; 1,628558370192401
+1483,4109724050659; 1,4241031945513674
+2002,568136043121; 1,2616407836292618
+3045,8553406742876; 1,09372808300933
+4983,9913111605565; 0,8886628824162796
+10116,086432495827; 0,6593474448589979

WPDigitalizer/MQ2/CH4.csv

@@ -0,0 +1,9 @@
+200,6424043638923; 3,0628594206904824
+493,62843297110385; 2,262307524341795
+795,3985507023424; 1,9027463399615197
+1021,3853885815306; 1,760109364516406
+1466,3881949840988; 1,512822440016997
+2010,2873757128875; 1,3635579819828156
+3022,508881097584; 1,1618613226754184
+4945,78905312065; 0,9359079659557669
+10155,080609166793; 0,7034431020028873

WPDigitalizer/MQ2/CO.csv

@@ -0,0 +1,9 @@
+202,97159045689085; 5,230578600305607
+491,73296457790207; 4,06886745979215
+810,8471866516105; 3,4816976949280916
+994,2457296427418; 3,220835982615804
+1483,4109724050659; 2,8043001628397395
+2025,8152351174235; 2,505895099093425
+3045,8553406742876; 2,2293985477843727
+4983,9913111605565; 1,84294785992263
+10272,967317129345; 1,4525325413623644