MQ-135 Air Quallty Sensor

Sensitive material MQ135 gas sensor is used in clean air low conductivity tin oxide (SnO2). When the sensor is kept in their environment In the polluting gases , the conductivity sensor with increasing air pollution in gas concentration increases.

- Using a simple circuit can change the conductivity Conversion of an output signal corresponding to the gas concentration .
- MQ135 sensor for ammonia, sulfide , benzene vapor high sensitivity of the smoke and other harmful monitor is also very good. This sensor can be seized measure a variety of harmful gases , is a low-cost sensors for a variety of applications .

Specifications:
1. It adopts high quality double panel design with power indication and TTL signal output indication;
2. It has DO switch signal (TTL) output and AO analog signal output;
3. The TTL output valid signal is low. (When the output is low, the signal light is on, it can be directly connected to the MCU or relay module)
4. The voltage of the analog output, the higher the concentration, the higher the voltage.
5. It has good sensitivity to gas and natural gas detection.
6, there are four screw holes for easy positioning;
7, product dimensions: 32 (L) * 20 (W) * 22 (H)
8, has a long service life and reliable stability
9, fast response recovery characteristics

Electrical Performance:
Detection of gas: Ammonia /Sulfide/ Benzene vapor
Detection of Concentration:10-1000ppm
Input voltage: DC5V
Power consumption (current): 150mA
DO output: TTL digital quantities 0 and 1 (0.1 and 5V)
AO output: 0.1-0.3V (relatively non-polluting), the highest concentration voltage is about 4V
Using the chip: AT89S52
Crystal: 11.0592MHZ
Baud rate: 9600
Compilation environment: Keil
Special Reminder:
After the sensor is energized, it needs to be preheated for about 20S, and the measured data is stable. The heating of the sensor is a normal phenomenon, because there is a heating wire inside, if it is hot, it is not normal.

Application:
A hazardous gas detection apparatus for the family, the environment. Suitable for ammonia, aromatic compounds, sulfur, benzene vapor, smoke and other gases harmful gas detection. Gas-sensitive element test concentration range: 10 to 1000ppm