MQ-135 Sensor Air Quality Sensor Hazardous Gas Detector Module fr Arduino AVR

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.
Air quality sensor is for detecting a wide range of gases, including NH3, NOx, alcohol, benzene, smoke and CO2. Ideal for use in office or factory, simple drive and monitoring circuit.
The main chip: LM393, MQ135 gas sensing probe
Operating voltage: DC 5V
Feature:
? Signal output indicator instructions;
? Dual signal output (analog output, and TTL level output);
? TTL output valid signal is low; (output low signal light, which can be accessed microcontroller IO port)
? Analog output with increasing concentration, the higher the concentration, the higher the voltage;
? Sulfide, benzene Department of steam, smoke and other harmful gases with high sensitivity;
? Has a long life and reliable stability;
? Rapid response recovery characteristics;