Description :
Sensitive material of MQ 137 gas sensor is Sn02 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 137 gas sensor has high sensitivity to Ammonia, also to the other organic amine. The sensor could be used to detect different gas which contains Ammonia, it is with low cost and suitable for different application.
Character :
- Good sensitivity to Ammonia
- Long life and low cost
- Simple drive circuit
Application :
- Domestic Ammonia detector
- Industrial Ammonia gas sensor
- Portable gas sensor
Configuration :
Technical Data :
Basic test loop
The figure above is a basic test circuit of the sensor. The sensor need to put 2 voltage, heater voltage ( VH ) and test voltage ( VC ). VH used to supply certified working temperature to the sensor, while VC used to detect voltage ( VRL ) on load resistance ( RL ) whom is in series with sensor. The sensor has light polarity, Vc need DC power. VC and VH could use same power circuit with precondition to assure performance of sensor. In order to make the sensor with better performance, suitable RL value is needed :
Resistance of Sensor ( Rs ) : Rs = ( Vc/VRL - 1 ) x RL
Sensitivity Characteristics :
Figure above shows the typical sensitivity characteristics of the MQ 137, ordinate means resistance ratio of the sensor ( Rs / Ro ), abscissa is concentration of gases. Rs means resistance in different gases, Ro means resistance of sensor in 550ppm ethanol. All test are under standard test conditions.
PS : Sensitivity to smoke is ignite 10pcs cigarettes in
Influence of Temperature / Humidity :
Figure above shows the typical temperature and humidity characteristic. Ordinate means resistance ratio of the sensor ( Rd / Ro ), Rs means resistance of sensor in 50ppm NH3 under different temperature and humidity.
Structure and configuration :
Structure and configuration of MQ 137 gas sensor as shows at figure above, sensor composed by micro AL203 ceramic tube, Tin Dioxide ( Sn02 ) sensitivity layer, measuring electrode and heater are fixed into a crust by plastic and stainless steel net. The heater provides necessary work conditions for sensitive components. The enveloped MQ-4 have 6 pin, 4 of them are used to fetch signals, and other 2 used for providing heating current.
2) MQ 138 Semiconductor Sensor for Organic Steam.
Description :
Sensitive material of MQ 137 gas sensor is Sn02 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 138 gas sensor has high sensitivity to Toluene, Acetone, Ethanol and Formaldehyde also to the other organic steam. The sensor could be used to detect different organic steam, it is with low cost and suitable for different application.
Character :
- Good sensitivity to Organic Steam
- High sensitivity to Toluene, Acetone and Ethanol
- Long life and low cost
- Simple drive circuit
Application :
- Domestic Organic steam detector
- Industrial Organic steam detector
- Portable gas detector
Technical Data :
Basic test loop
The figure above is a basic test circuit of the sensor. The sensor need to put 2 voltage, heater voltage ( VH ) and test voltage ( VC ). VH used to supply certified working temperature to the sensor, while VC used to detect voltage ( VRL ) on load resistance ( RL ) whom is in series with sensor. The sensor has light polarity, Vc need DC power. VC and VH could use same power circuit with precondition to assure performance of sensor. In order to make the sensor with better performance, suitable RL value is needed :
Resistance of Sensor ( Rs ) : Rs = ( Vc/VRL - 1 ) x RL
Sensitivity Characteristics :
Graph above shows the typical sensitivity characteristics of the MQ 138, ordinate means resistance ratio of the sensor ( Rs / Ro ), abscissa is concentration of gases. Rs means resistance in different gases, Ro means resistance of sensor in 100ppm Toluene. All test are under standard test conditions.
Influence of Temperature / Humidity :
Figure above shows the typical temperature and humidity characteristic. Ordinate means resistance ratio of the sensor ( Rd / Ro ), Rs means resistance of sensor in 100ppm Toluene under different temperature and humidity. Ro means resistance of the sensor in environment of 100ppm Toluene, 20C/65%RH.
Structure and configuration :
Structure and configuration of MQ 138 gas sensor as shows at figure above, sensor composed by micro AL203 ceramic tube, Tin Dioxide ( Sn02 ) sensitivity layer, measuring electrode and heater are fixed into a crust made by plastic and stainless steel net. The heater provides necessary work conditions for sensitive components. The enveloped MQ-4 have 6 pin, 4 of them are used to fetch signals, and other 2 used for providing heating current.
3) MQ 2 Semiconductor Sensor for Combustible Gas.
Description :
Sensitive material of MQ 2 gas sensor is Sn02 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 sensitivity to LPG, Propane and Hydrogen, also could be to Methane and other combustible steam, it is with low cost and suitable for different application.
Character :
- 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 sensor.
- Portable gas sensor.
Configuration :
Technical data :
Basic test loop :
The figure above is the basic test circuit of the sensor. The sensor need to be put 2 voltage, heater voltage ( VH ) and test voltage ( VC ). VH used to supply certified working temperature to the sensor, while VC used to detect voltage ( VRL ) on load resistance ( RL ) whom is in series with sensor. The sensor has light polarity, Vc nedd DC power. VC and VH could use same power circuit with precondition to assure performance of sensor with better performance, suitbale RL value is needed :
Sensitivity Characteristics :
Graph shown above is the typical sensitivity characteristics of the MQ 2, ordinate means resistance ration of the sensor ( Rs / Ro ), abscissa is concentration of gases. Rs means resistance in different gases, Ro means resistance of sensor in 1000ppm Hydrogen. All test are under standard test condition.
Influence of Temperature/ Humidity :
Graph above shown 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 temperature and humidity. Ro means resistance of the sensor in environment of 1000ppm Methane.
Structure and configuration :
Structure and configuration of MQ 2 gas sensor is shows at above, sensor composed by micro AL203 ceramic tube, Tin Dioxide ( Sn02 ) 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 for providing heating current.
4) MQ 4 Semiconductor Sensor for Smoke and LPG.
