Henan Hanwei Electronics Co., Ltd www.hwsensor.com MQ-9 Semiconductor Sensor for CO/Combustible Gas Sensitive material of MQ-9 gas sensor is SnO which with lower conductivity in clean air. It make 2, detection by method of cycle high and low temperature, and detect CO when low temperature (heated by 1.5V). The sensors 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 V V R Model No. MQ-9 Sensor Type Semiconductor Standard Encapsulation Bakelite R Detection Gas CO and combustible gas L V H 10-1000ppm CO Concentration 100-10000ppm combustible gas Loop Voltage V 10V DC c GND 5.0V0.2V ACorDCHigh Heater Voltage V H 1.5V0.1V ACorDCLow Circuit The above is basic test circuit of the Heater Time T 601SHigh901SLow L sensor. The sensor need to be put 2 Load Resistance R Adjustable L voltage, heater voltageVH and Heater Resistance R 313Room Tem. test voltageVC. VH used to H Heater supply certified working temperature P 350mW H consumption to the sensor, while VC used to Sensing Character R 2K-20K (in 100ppm CO ) s Resistance detect voltage (VRL) on load Sensitivity S Rs(in air)/Rs(100ppm CO) 5 resistanceRLwhom is in series Slope 0.6(R /R CO) 300ppm 100ppm with sensor. The sensor has light Tem. Humidity 202 65%5%RH polarity, Vc need DC power. VC and Vc:5.0V0.1V VH could use same power circuit V High: 5.0V0.1V Condition Standard test circuit H with precondition to assure V Low: 1.5V0.1V H performance of sensor. In order to Preheat time Over 48 hours make the sensor with better performance, suitable RL value is needed: 2 2 Power of Sensitivity body(Ps): Ps=Vc Rs/(Rs+RL) Tel: 86-371-67169070/80 Fax: 86-371-67169090 Email: sales hwsensor.com Henan Hanwei Electronics Co., Ltd www.hwsensor.com 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 MQ-9, 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 resistance in different gases, Ro means resistance of in 1000ppm Propane under different tem. and humidity. sensor in 1000ppm LPG. All test are under standard Ro means resistance of the sensor in environment of test conditions. 1000ppm Propane, 20/65%RH 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