Zhengzhou Winsen Electronics Technology Co., Ltd
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Basic Circuit
Fig2. MQ-2 Test Circuit
Instructions: The above fig is the basic test circuit of MQ-2.The sensor requires two voltage inputs:
heater voltage(V
H
) and circuit voltage(V
C
). V
H
is used to supply standard working temperature to
the sensor and it can adopts DC or AC power, while V
RL
is the voltage of load resistance R
L
which is
in series with sensor. Vc supplies the detect voltage to load resistance R
L
and it should adopts DC
power.
Description of Sensor Characters
NOTE: Output voltage(Vs) is V
RL
in test environment.
Fig3.Typical Sensitivity Curve
The ordinate is resistance ratio of the sensor (Rs/R
0
), the
abscissa is concentration of gases. Rs means resistance in
target gas with different concentration, R
0
means
resistance of sensor in clean air. All tests are finished
under standard test conditions.
Fig4.Typical temperature/humidity characteristics
The ordinate is resistance ratio of the sensor (Rs/Rso).Rs
means resistance of sensor in 2000ppm propane(C
3
H
8
)
under different tem. and humidity. Rso means resistance of
the sensor in 2000ppm propane under 20
℃
/55%RH.
C
3
H
8
Air
CH
4
Alcohol
Smoke
Concentration
