HANWEI ELETRONICS CO.,LTD
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.
Electric parameter measurement circuit is shown as Fig.2
E. Sensitivity characteristic curve
Fig.2 sensitivity characteristics of the MQ-2
Fig.3 is shows the typical
sensitivity characteristics of
the MQ-2 for several gases.
in their: Temp: 20℃、
O2 concentration 21%
Ro: sensor resistance at 1000ppm of
H2 in the clean air.
Rs:sensor resistance at various
concentrations of gases.
Fig.4 is shows the typical dependence of
the MQ-2 on temperature and humidity.
Ro: sensor resistance at 1000ppm of H2 in air
at 33%RH and 20 degree.
Rs: sensor resistance at 1000ppm of H2
at different temperatures and humidities.
Resistance value of MQ-2 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 liquified petroleum gas<LPG>,or 1000ppm iso-butane<i-C4H10>concentration in air and use value of
Load resistance that( RL) about 20 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.
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