Electrobot MQ135 Air Quality and Hazardous Gas Detection Sensor Module for Arduino Raspberry Pi Gas Sensor

Sensitive material MQ135 gas sensor is used in clean air low conductivity tin oxide (SnO2) when the sensor is kept in their environment.>>>>> Module Applications: 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. has a long life and reliable stability. 8. Rapid response and recovery characteristics.>>>>> Electrical properties: Input voltage: DC 5V 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.>>>>> Important Instruction: After the sensor is powered on, it needs to preheat 20S or so, and the measured data is stable. The sensor heating is a normal phenomenon, because there is a heating wire inside, it is abnormal if it is hot.