Target: CH4,C3H8
Model: GM-402B
Detection range: 1-10000ppm
Detection principle: Semiconductor、MEMS
Characteristics: High sensitivity to combustible gases, small sizes and low power consumption
Size: 5×5×1.55
Working conditions: Loop Voltage:≤24V Heater Voltage:2.8±0.1V Heater consumption:≤80mW

GM-402B Manual download
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MEMS combustible gas sensor is using MEMS micro-fabrication hot plate on a Si substrate base, gas-sensitive materials used in the clean air with low conductivity metal oxide semiconductor material. When the sensor exposed to gas atmosphere, the conductivity is changing as the detected gas concentration in the air. The higher the concentration of the gas, the higher the conductivity. Use simple circuit can convert the change of conductivity of the gas concentration corresponding to the output signal.


Gas leak detection for mobile phones, computers and other consumer electronics applications; also apply for home, commercial use of the combustible gas leakage monitoring devices, gas leak detectors, fire / security detection system.


  • MEMS technology, Strong construction
  • High sensitivity to combustible gases
  • Small sizes and low power consumption
  • Fast response and resume
  • Simple drive circuit, Long lifespan


Part No. GM-402B
Sensor Type MEMS
Standard Encapsulation Ceramic
Detection Gas CH4, C3H8 &etc.
Detection Range 1~10000ppm (C3H8)
Standard Circuit Conditions Loop Voltage VC ≤24V DC
Heater Voltage VH 2.8V±0.1V AC or DC
Load Resistance RL Adjustable
Sensor character under standard test conditions Heater Resistance RH 80Ω±20Ω(room temperature)
Heater consumption PH ≤80mW
sensitive materials resistance RS 1KΩ~30KΩ(in 5000ppm CH4)
Sensitivity S R0(in air)/Rs(in 5000ppmCH4)≥2
Concentration slope α ≤0.9(R5000ppm/R1000ppmCH4)
Standard test conditions Temp. Humidity 20℃±2℃;55%±5%RH
Standard test circuit VH:2.8V±0.1V;VC:5.0V±0.1V

* The description and specifications might be changed without notice. Please contact us for the latest information before placing orders.

Technical Support:

Customized technical design and function, LOGO and package are available without extra charge (including molding fee) for mass volume.

The sensors don't have sleeping mode. It can be set in program if needed.

All Winsen products go through strict inspections and tests to make sure they are 100% qualified before shipping out.

The sensor has been fully tested (not calibrated) before leaving the factory. However, after transportation and storage, the environment conditions change, and the surface of the sensor absorbs moisture, mixed gas, pollution matters, etc. It is recommended that customers perform aging and calibration after sensors become stable according to the program and use occasions of the whole device.

15﹪-90﹪RH without condensation,greater or less than this range or long-term high temperature and high humidity will affect the life of the sensor.

Our sensors are certified with CE, 3C, ROHS, anti-explosion, fire prevention, and coal mining safety according to different applications. And we provide assistance for new certification.

Many factors can cause the sensor to fail such as broken wires in transportation, poisoning, falling off of the sensitive material, damage to the heating wire (device), etc. Please find specific cause in each category with Winsen’s aftersales.

Winsen provides professional consultation and service before and after sales. We will recommend the best fitting sensor for your demand. If you have any problem, don’t hesitate to email us to

Due to high volume of daily incoming emails and time zone difference, we may not be able to reply your emails immediately. But we will reply to your inquiry in 24 business hours.