Data Sheet

HANWEI ELETRONICS CO.,LTD MQ-3 http://www.hwsensor.com
TEL: [phone] 67169080 FAX: [phone] E-mail: [e-mail]
TECHNICAL DATA MQ-3 GAS SENSOR
FEATURES
* High sensitivity to alcohol and small sensitivity to Benzine .
* Fast response and High sensitivity
* Stable and long life
* Simple drive circuit
APPLICATION
They are suitable for alcohol checker, Breathalyser.
SPECIFICATIONS
A. Standard work condition
Symbol Parameter name Technical condition Remarks
Vc Circuit voltage 5V±0.1 AC OR DC
V
H
Heating voltage 5V±0.1 ACOR DC
R
L
Load resistance
200KΩ
R
H
Heater resistance
33Ω±5%
Room Tem
P
H
Heating consumption less than 750mw
B. Environment condition
Symbol Parameter name Technical condition Remarks
Tao Using Tem
-10℃-50℃
Tas Storage Tem
-20℃-70℃
R
H
Related humidity less than 95%Rh
O
2
Oxygen concentration 21%(standard condition)Oxygen
concentration can affect sensitivity
minimum value is
over 2%
C. Sensitivity characteristic
Symbol Parameter name Technical parameter Remarks
Rs Sensing Resistance
1MΩ- 8 MΩ
(0.4mg/L alcohol )
α
(0.4/1 mg/L)
Concentration slope rate
≤0.6
Standard
detecting
condition
Temp: 20℃±2℃ Vc:5V±0.1
Humidity: 65%±5% Vh: 5V±0.1
Preheat time Over 24 hour
Detecting concentration
scope：
0.05mg/L—10mg/L
Alcohol
D. Structure and configuration, basic measuring circuit
Parts Materials
1 Gas sensing
layer
SnO
2
2 Electrode Au
3 Electrode line Pt
4 Heater coil Ni-Cr alloy
5 Tubular ceramic Al
2
O
3
6 Anti-explosion
network
Stainless steel gauze
(SUS316 100-mesh)
7 Clamp ring Copper plating Ni
8 Resin base Bakelite
9 Tube Pin Copper plating Ni
A向
A向
Fig. 1
Configuration A Configuration B
Fig.2