1. Using high-quality dual-panel design, with power indicator and TTL signal output instructions
2. there are four screw holes for easy positioning
3. Analog output voltage with the higher concentration of higher voltage
4. TTL output valid signal is low. (Low-level signal when the output light can be directly connected to the microcontroller or relay module)
5. The switching signal having a DO (TTL) output and analog output AO

Special note:
After the sensor is powered, needs wait about 20S, measured data was stable, heat sensor is a normal phenomenon, because the internal heating wire.

Specifications:

Size: 32 x 22 x 27mm
Chip: LM393, ZYMQ-2 gas sensors
Working voltage: DC 5V
AO output :0.1-0 .3 V (relative to pollution), the maximum concentration of a voltage of about 4V
DO output: TTL digital 0 and 1 (0.1 and 5V)
Input voltage: DC5V Power consumption (current): 150mA

Package included:

1 x MQ-2 gas sensor module