MQ-6 GAS SENSOR
* High sensitivity to LPG, iso-butane, propane
* Small sensitivity to alcohol, smoke.
* Fast response . * Stable and long life * Simple drive circuit
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.
A. Standard work condition
Vc Circuit voltage
VH Heating voltage
PL Load resistance
RH Heater resistance
PH Heating consumption
B. Environment condition
less than 750mw
AC OR DC
RH Related humidity
less than 95%Rh
minimum value is
concentration can affect sensitivity over 2%
C. Sensitivity characteristic
(1000ppm LPG )
Concentration slope rate
Temp: 20℃±2℃ Vc:5V±0.1
Humidity: 65%±5% Vh: 5V±0.1
LPG , iso-butane,
Over 24 hour
D. Strucyure and configuration, basic measuring circuit
1 Gas sensing
3 Electrode line
4 Heater coil
5 Tubular ceramic
7 Clamp ring
8 Resin base
9 Tube Pin
Stainless steel gauze
Copper plating Ni
Copper plating Ni
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
Fig.3 is shows the typical
sensitivity characteristics of
the MQ-6 for several gases.
in their: Temp: 20℃、
O2 concentration 21%
Ro: sensor resistance at 1000ppm of
LPG in the clean air.
Rs:sensor resistance at various
concentrations of gases.
Fig.4 is shows the typical dependence of
the MQ-6 on temperature and humidity.
Ro: sensor resistance at 1000ppm of LPG in air
at 33%RH and 20 degree.
Rs: sensor resistance at 1000ppm of LPG in air
at different temperatures and humidities.
10 20 30 40 50
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.
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