[Discontinued] MQ-135 Air Quality Sensor Hazardous Gas Detection Sensor
MQ-135 module is widely used in air quality control equipments for buildings/offices, are suitable for detecting of NH3,NOx, alcohol, Benzene, smoke,CO2 ,etc
- Wide detecting scope
- Fast response and High sensitivity
- Stable and long life
- Simple drive circuit
- The main chip: LM393, MQ135 gas sensing probe
- Operating voltage: DC 5V
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.
1. Signal output indicator instructions;
2. Dual signal output (analog output, and TTL level output);
3. TTL output valid signal is low; (output low signal light, which can be accessed microcontroller IO port)
4. Analog output with increasing concentration, the higher the concentration, the higher the voltage;
5. Sulfide, benzene Department of steam, smoke and other harmful gases with high sensitivity;
6. Has a long life and reliable stability;
7. Rapid response recovery characteristics;
WHAT'S IN THE PACKAGE
- 1 x MQ-135 Air Quality Sensor Module
Very nice little module. There is an analog and digital pin for getting readings. The analog pin outputs higher voltages as the gas concentration increases, the digital pin signals a threshold of gas concentration has been crossed, changing from low to high state. You can change that threshold with the little potentiometer on the back of the module. With a 5V power source, you might be able to bypass an Arduino altogether if you just needed a simple 5V signal (for a relay or something)-- I have not verified this though. It will measure more than just ammonia, for example it can detect the C02 in your breath or other volatile chemicals. That's right, your breath is volatile. 4 stars because there is no real documentation or example codes on SainSmart's website.
Worked as expected for my project. The sensor was very sensitive and responded quickly to being exposed to various gases, including alcohol. The data sheet leaves a lot to be desired but, no worse than expected from a typical Chinese tech product.