Description: 

The gas sensing material used in the MQ-4 gas sensor is two tin oxide (SnO2), which has a lower conductivity in clean air. The electrical conductivity of the sensor increases with the increase of the concentration of combustible gas in the air when the sensor is in the presence of combustible gas. A simple circuit is used to convert the change of electrical conductivity to the output signal corresponding to the gas concentration. 

The sensitivity of MQ-4 gas sensor to methane is high, and it has a better sensitivity for propane and. This sensor can detect a variety of combustible gases, especially natural gas, is a suitable for a wide range of applications of low-cost sensors. 

characteristic 
* good sensitivity to combustible gas in a wide range of concentration. 
* the sensitivity of methane is higher. 
* long life, low cost 
* simple drive circuit 

Application 

* household gas leak alarm 

* Combustible gas alarm for industrial use 

* portable gas detector 


Product model 

MQ-4 

product type 

Semiconductor gas sensor 

Standard package 

Bakelite 

Gas detection 

Natural gas, methane 

Detection concentration 

300-10000ppm (methane, natural gas) 

Standard circuit conditions 

Loop voltage 

Vc 

DC = 24V 

Heating voltage 

VH 

5.0V + ACorDC 0.2V 

Load resistance 

RL 

Adjustable 

Characteristics of gas sensors under standard test conditions 

Heating resistance 

RH 

31 + 3 (Shi Wen) 

Heating power consumption 

PH 

Less than 900mW 

Sensitive surface resistance 

Rs 

2K -20K (in CH4) (5000ppm) 

sensitivity 

S 

Rs (in air) /Rs (5000ppm methane) = 5 

Concentration slope 

Alpha 

Less than 0.6 (R5000ppm/R3000ppmCH4) 

Standard test conditions 

Temperature and humidity 

20 C + 2 C; 65% + 5%RH 

Standard test circuit 

Vc:5.0V + 0.1V; 

5.0V VH: + 0.1V