– The gas sensing material used in the MQ-4 gas sensor is tin dioxide (SnO2) with low conductivity in clean air.

– When there is a flammable gas in the environment where the sensor is located, the conductivity of the sensor increases as the concentration of flammable gas in the air increases.

– A simple circuit can be used to convert the change in conductivity into an output signal corresponding to the gas concentration.

– The MQ-4 gas sensor has high sensitivity to butane, propane and methane, and has a good balance between methane and propane.

– This sensor detects a wide range of flammable gases, especially natural gas, and is a low cost sensor for a variety of applications.

– Suitable for monitoring equipment for liquefied gases, natural gas and gas in the home or industry. Excellent resistance to ethanol and smoke.

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

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

1 x MQ-4 Gas Sensor Module