Working Principle and Advantages of Semiconductor Methane Sensors

Methane (CH₄) is not only an important clean energy, but also a potential source of danger in energy exploitation, industrial production and even daily life. In 2020 natural gas pipeline leakage in California led to 160,000 tons of methane entering the atmosphere and in 2022 a gas explosion in a coal mine in Shanxi caused 15 deaths, these accidents constantly warn the importance of methane monitoring. Semiconductor methane sensors are precisely a type of “electronic nose” created by modern technology, silently guarding the safety of human production and life.

1. Working principle: the "electrical signal translator" of REDOX reactions

The core of a semiconductor methane sensor is the metal oxide semiconductor material (e.g., SnO₂) coated on a ceramic substrate. When the methane sensor is heated to 200-400°C, oxygen molecules on its surface will capture free electrons in the semiconductor, forming negative ions of oxygen (O-). At this point, if it encounters a methane molecule, the following reaction will occur:

CH₄ + 4O⁻ → CO₂ + 2H₂O + 4e⁻

The electrons released return to the semiconductor, resulting in a decrease in material resistance. The change in resistance is detected by a sophisticated circuit and converted into a methane concentration. The whole process resembles an “electron dance” in the microscopic world, with the methane sensor acting as a real-time “translator”.

2. Technical advantage: A powerful tool for miniaturized intelligent monitoring

Compared with catalytic combustion and infrared absorption sensors, semiconductor methane sensors exhibit unique advantages:

ü The cost of mass production can be controlled within a few dozens of yuan, 1/10 of the cost of infrared sensors

ü Quick response: suitable for leakage alarm

ü Can be manufactured using MEMS technology: chip-level package (3 × 3 × 1mm)

ü Long life design: 10 years to semi-permanent life

Taking the pipeline renovation of a gas company in Shenzhen as an example, after deploying 8,000 semiconductor methane sensors, the time to locate leaks was reduced from 2 hours to 8 minutes, and the annual maintenance costs were reduced by 65%.

3. Application graph: Full-scenario protection from mines to kitchens

PetroChina has set up sensor nodes every 200 meters in the pipeline in Sichuan and Chongqing area, and a gas company in Hangzhou has adopted a three-dimensional monitoring network of “sensors + Internet of Things”. Semiconductor methane sensor is the best choice for early warning of natural gas leakage in the kitchen.

4. Eursense module introduction

Semiconductor gas sensor detects LP propane with Figaro TGS 2619 - AG-2-CH4-M2619(D)

Product Specification

The AG-2-CH4-M2619(D) is an embedded type module equipped with the Figaro’s semiconductor Sensor TGS2619; the module has been pre-calibrated before leaving the factory and it includes a specialized filter that reduces interference from gases like alcohol, ensuring a selective response to methane (CH4). It utilizes digital communication through a USART and a programmable Alarm output interface for gas concentration readings. This allows users to easily and quickly integrate the module into residential gas leakage alarm systems, such as household natural gas detectors.

Features

ü High selectivity to methane

ü Long life and low cost

ü Alarm output

ü USART digital output

ü pre-calibrated before leaving the factory

Technical Specification