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Gh-312 gas sensor operation

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New Member
I wanted an MQ6 LPG sensor, but I was able to get GH-312 gas sensor. I realized that I can not measure the percentage concentration of gas since it outputs a low or high upon detection. I thought I could get the output voltage varying according to concentration.
Please, how do i get around this? I don't just want to detect gas, but the percentage of concentration.


Well-Known Member
GH-312 is not a gas sensor, it is a module. The module contains an MQ-2 sensor, which you can unsolder. The MQ-2 sensor detects a different range of gasses than the MQ-6.


Well-Known Member
Most Helpful Member
This is all I could find on the thing:

Smoke Gas Butane Propane Smoke Sensor Module Smoke Detector GH312
- With the signal output instructions
- The dual signal output; (analog output, and TTL level output)
- TTL output valid signal is low, which can be accessed directly connected to Microcontroller IO port
- 0 ~ 5V analog output voltage, the higher the voltage the higher the concentration

- Liquefied gas, butane, methane, smoke, etc. have good sensitivity
- Long life, good stability
- With fast response and recovery characteristics

Electrical parameters:
- GAS sensor : Wide detection range
- With LED : Alarming
- Static Power : < 0.8 W
- Output Level : High5 V / Low 0V
- Detection of Square : 10㎡
- Size : 33.5mm * 21.5mm
- Simple to use : Power + - signal output
- Operating voltage DC voltage 9-20V
- Static power consumption less than 0.8W
- Output Level High 5 V / Low 0V
- Detection area of 10 square meters
- smoke, gas, butane, propane
- Methane, ethanol, hydrogen, etc.
Packing Included
- Smoke Sensor x1
All I see is conflicting nonsense? The device has 3 pins that I can see. Power, Common and Signal Out. The only data sheet I saw was in Chinese. While they mention an analog signal out I see none so I really don't know what to say. Do you have a link to a good valid data sheet?

<EDIT> Ah, I see Duffy has a handle on it. So the sensor is actually MQ-2 and the thing is a module using the MQ-2 which can be removed and used? Everything I read confused the hell out of me. Thanks Duffy. </EDIT>

Last edited:


New Member
Thank you very much for the information. Now i know I can desolder and use the sensor. I will check for the pin configuration of MQ-2 so that I can study the voltage response to gases.
I believe that it works by changes in resistance? i will find out. Thanks
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