Product Review

MQ-135 MQ135 Air Quality Sensor Hazardous Gas Detection Module For Arduino AVR
Module Applications:
Probe for home, environmental harmful gas detection device, suitable to ammonia , aromatic compounds , sulfur compounds , benzene vapor , smoke and other gases harmful gases , the gas sensitive element concentration range : 10 to 1000ppm
Module Features:
1. Using high-quality dual-panel design, with power indicator and TTL signal output instructions;
2. The switching signal having a DO (TTL) output and analog output AO;
3. TTL output valid signal is low. ( Low-level signal when the output light can be directly connected to the microcontroller or relay module )
4. The higher the voltage , the concentration of the analog output voltage is higher.
5. Air quality, hazardous gas detection with good sensitivity.
6. There are four screw holes for easy positioning;
7 Product dimensions: 32 (L) * 20 (W) * 22 (H)
8. Has a long life and reliable stability
9. Rapid response and recovery characteristics.
Electrical properties:
Input voltage: DC5V Power consumption ( current ): 150mA
DO output: TTL digital 0 and 1 ( 0.1 and 5V)
AO output :0.1-0 .3 V ( relative to pollution ) , the maximum concentration of a voltage of about 4V
Special note: After the sensor is powered , needs to warm up around 20S, measured data was stable, heat sensor is a normal phenomenon , because the internal heating wire , if hot is not normal.
Wiring:
1. VCC: positive power supply (5V)
2. GND: power supply is negative
3. DO: TTL switching signal output
4. AO: analog signal output