MQ-3 alcohol gas detection module ethano...

MQ-3 sensor profile:
MQ-3 gas sensor is sensitive material used in clean air, low conductivity tin dioxide (SnO2). When the sensor is present in the environment in which the alcohol vapor , the sensor's conductivity increases with the concentration of alcohol gas in the air increases. Using a simple circuit can be converted to the change in conductivity of the gas concentration with the corresponding output signal. MQ-3 gas sensor with high sensitivity to alcohol , gasoline can resist , smoke , water vapor interference. This sensor can detect various concentrations of alcohol atmosphere , is a low-cost sensors for a variety of applications

Module Applications:
Alcohol ( ethanol ) testing for motor vehicle drivers and other non- drinking and operating personnel on-site testing, but also for other places ethanol vapor detection

Module Features :
1 , using high-quality dual-panel design, with power indicator and TTL signal output instructions ;
2, with a DO switch signal (TTL) output and AO analog signal output ;
3, TTL output valid signal is low . ( When the output low signal light can be directly connected microcontroller or relay module )
4 , the analog output voltage , the higher the concentration the higher the voltage .
5 , there is a good test for alcohol sensitivity.
6 , there are four screw holes for easy positioning ;
7 Product dimensions : 35.5 (L) * 22.5 (W) * 23 (H)
8, with a long service life and reliable stability
9 , rapid response and recovery characteristics

Electrical properties:
Input voltage: DC5V power ( current ): 150mA
DO output : TTL digital 0 and 1 ( 0.1 and 3.3V)
AO output :0.1-0 .3 V ( relatively clean ) , the highest concentration of voltage around 4V
Special note : The sensor is powered, needs to warm up around 20S , measured data becomes stable , the sensor fever is a normal phenomenon, because the internal heating wire , if hot is not normal.

Wiring:
1, VCC: positive power supply (5V)
2, GND: tied to power supply
3, DO: TTL switching signal output
4, AO: analog output