NDIR Methane CH4 Gas Sensor 0-100%LEL with UART Output

MNS-QT331 NDIR Methane CH4 Gas Sensor

The MANORSHI MNS-QT331 NDIR Methane Gas Sensor is developed for accurate and stable detection of methane (CH4) concentration in industrial, commercial and gas safety applications.

Unlike conventional catalytic combustible gas sensors, the MNS-QT331 uses NDIR (Non-Dispersive Infrared) technology to detect methane through its characteristic infrared absorption wavelength. This sensing method provides good long-term stability, strong resistance to poisoning and reduced sensitivity to environmental interference.

With multiple selectable measurement ranges and both digital and analog interfaces, the sensor can be easily integrated into methane detectors, gas alarm systems, portable detection instruments and OEM gas monitoring equipment.

Key Features

• NDIR infrared methane detection technology

• Designed for CH4 / methane gas measurement

• Multiple ranges available: 0-100%LEL, 0-5%Vol and 0-100%Vol

• Accuracy up to ±5%FS

• Fast response: T90 <30 seconds

• UART digital output

• 0.4-2V analog voltage output

• Operating voltage: 3.3-5VDC

• Built-in temperature compensation

• Excellent long-term measurement stability

• Strong resistance to water vapor interference

• Non-poisoning infrared sensing principle

• Low average current consumption of <85mA

• Wide operating temperature range

• IP65 protection

• Expected lifespan of more than 5 years

• Compact cylindrical design for OEM integration

NDIR Methane Detection Principle

The MNS-QT331 uses the Non-Dispersive Infrared absorption principle for methane concentration measurement.

An infrared light source emits infrared radiation through the gas sampling chamber. Methane molecules absorb infrared energy at specific wavelengths. The infrared detector measures the change in received infrared intensity and the internal electronics calculate the methane concentration according to the absorption characteristics.

Because NDIR sensing does not depend on catalytic combustion reactions, the sensor offers advantages such as good stability, resistance to poisoning and long operating life.

Technical Specifications

Output Interfaces

The MNS-QT331 supports both UART communication and analog voltage output, making it suitable for integration with different gas detection control systems.

Pin Definition

The dual-output design allows OEM manufacturers to integrate the sensor into embedded controllers, gas detectors and intelligent monitoring equipment.

Available Methane Measurement Ranges

Different applications require different methane concentration ranges. The MNS-QT331 can be configured for several common ranges:

0-100%LEL

Suitable for combustible gas alarms, methane leakage detection, industrial safety monitoring and natural gas detection.

0-5%Vol

Suitable for applications requiring methane concentration measurement around the lower explosive range.

0-100%Vol

Suitable for high-concentration methane measurement, gas analysis and process monitoring applications.

For OEM projects, the appropriate methane sensor range can be selected according to the required application.

Typical Applications

The MNS-QT331 methane gas sensor can be integrated into:

• Natural gas leak detectors

• Methane gas alarms

• Industrial combustible gas detectors

• Portable gas detection instruments

• Fixed gas monitoring systems

• Smart home gas detectors

• Natural gas equipment

• Mine methane monitoring equipment

• Gas analyzers

• Environmental monitoring equipment

• Industrial safety systems

• IoT gas monitoring terminals

• OEM methane detection devices

Why Use an NDIR Methane Sensor?

NDIR technology is particularly suitable for methane measurement because methane has characteristic infrared absorption bands that can be selectively detected.

Compared with some conventional combustible gas detection technologies, NDIR methane sensors provide several practical benefits for OEM equipment manufacturers:

Long-term stability: infrared measurement reduces degradation caused by catalytic reactions.

Resistance to poisoning: the sensing principle is not based on a catalytic bead surface.

High methane selectivity: optical detection can be optimized for methane absorption characteristics.

Long service life: the MNS-QT331 is designed for a service life of more than five years under suitable operating conditions.

Low maintenance: stable optical measurement helps reduce frequent sensor replacement requirements.

Compact Design for OEM Integration

With a compact cylindrical structure and approximately 25 g weight, the MNS-QT331 can be integrated into portable and fixed methane detection equipment.

Its 3.3-5VDC operating voltage, UART interface and analog output make it suitable for integration with microcontrollers, embedded control boards and industrial gas detection electronics.

MANORSHI can also work with equipment manufacturers on sensor selection according to measurement range, output interface and application requirements.

FAQ

What gas does the MNS-QT331 detect?

The MNS-QT331 is designed primarily for methane (CH4) detection using NDIR infrared absorption technology.

What methane measurement ranges are available?

Available configurations include 0-100%LEL, 0-5%Vol and 0-100%Vol. The appropriate range should be selected according to the application.

What output signals does the methane sensor support?

The sensor supports UART digital output and 0.4-2V analog voltage output.

How fast is the response time?

The specified response time is T90 below 30 seconds.

Does the MNS-QT331 include temperature compensation?

Yes. The sensor includes temperature compensation to improve measurement stability across changing environmental temperatures.

What is the operating temperature range?

The standard operating range is approximately -40°C to +70°C. Wider or customized operating ranges may be available depending on project requirements.

What applications use an NDIR methane sensor?

Typical applications include methane leak detectors, natural gas alarms, industrial gas detectors, portable gas analyzers, smart gas monitoring devices and OEM combustible gas detection systems.