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 Parameter name Symbol Circuit voltage Vc VH Heating voltage Load resistance PL Heater resistance RH PH Heating consumption B. Environment condition Parameter name Using Tem Storage Tem Related humidity Oxygen concentration Symbol Tao Tas RH O2 C. Sensitivity characteristic Parameter name Sensing Resistance Symbol Rs Technical condition 5V ±0.1 5V ±0.1 20K Ω 31 ±10% less than 800mw Technical condition -10 ℃-50℃ -20 ℃-70℃ less than 95%Rh 21%(standard condition)Oxygen concentration can affect sensitivity Technical parameter 10K Ω- 60KΩ (5000ppm methane ) Remarks AC OR DC ACOR DC Room Tem Remarks minimum value is over 2% Remarks Detecting concentration scope： 200-10000ppm LPG,LNG Natural gas, iso-butane, propane Town gas α (5000ppm/1000 ppm CH 4) Standard detecting condition Preheat time Concentration slope rate ≤0.6 Temp: 20 ℃±2℃ Vc:5V ±0.1 Humidity: 65% ±5% Vh: 5V ±0.1 Over 24 hour D. Strucyure and configuration, basic measuring circuit Parts 1 Gas sensing layer Electrode Electrode line 2 3 4 Heater coil 5 6 Anti-explosion network 7 Clamp ring 8 Resin base 9 Tube Pin Tubular ceramic Al2O3 Materials SnO2 Au Pt Ni-Cr alloy Stainless steel gauze (SUS316 100-mesh) Copper plating Ni Bakelite Copper plating Ni Fig. 1 Fig.2 Configuration A 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 (SnO 2) 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 sensitivity characteristics of the MQ-5 MQ-5 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=20k Ω Ro: sensor resistance at 1000ppm of H2 in the clean air. Rs:sensor resistance at various concentrations of gases. Fig.2 10 1 o R / s R H2 LPG CH4 CO alcohol Air 0.1 100 o R / s R 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 1000 MQ-5 Fig.4 ppm 10000 Fig.4 is shows the typical dependence of the MQ-5 on temperature and humidity. Ro: sensor resistance at 1000ppm of H2 in air at 33%RH and 20 degree. Rs: sensor resistance at different temperatures and humidities. 33%RH 85%RH -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 47K Ω). 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