PLM30 Laser Methane Leak Detector (Portable / Vehicle-mounted)

PLM30 is a high-precision gas detection device based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology, specifically designed for real-time, non-contact detection of methane (CH4) gas leak. The device emits laser beam with a specific wavelength and utilizes the absorption characteristics of methane molecules in near-infrared spectrum to accurately analyze gas concentration and achieve quick and real-time leak detection. The detection accuracy can reach to PPM level (parts per million) and the response time is as short as milliseconds, which is significantly better than traditional detection techniques.

Overview

The device adopts modular design, which has the advantages of high sensitivity, strong anti-interference ability and long service life. It adapts to complex industrial environments such as natural gas pipelines, urban gas pipelines, chemical plants, gas storage stations, coal mines, etc. The non-contact detection mode does not require sampling, it can avoid the risk of sensor poisoning, the built-in intelligent algorithm can tell methane from other gas interference to reduce false alarm rates and help users quickly locate the leak points and promptly initiate emergency response.

The device adopts a full touch, high-brightness 3.7-inch LCD display screen, which displays the current methane content in real time with large numbers and displays the current methane content size through the height of the square column. It continuously displays the methane concentration value change curve for 200 seconds and displays the minimum methane content detected within a time period in real time. It can also record and view the methane content value at each location through the square column chart. The instrument can freely adjust the speed of the air pump to regulate the suction speed, and the detection mode is divided into leak detection mode and explosion detection mode. It has multiple characteristics such as high sensitivity, fast response, portable design, user friendliness, and data recording, and has been applied in various gas and oil pipeline scenarios to monitor methane leaks, analyze leak points, and prevent explosion risks. As a core tool for smart security and environmental monitoring, the laser methane leak detector has important value in ensuring the safe operation of energy facilities, reducing greenhouse gas emissions, and preventing explosion accidents. It is a key technical equipment for industrial safety and green development.

Principle of Laser Methane Detection

1. Functional Description

The core principle of laser methane detection is based on Tunable Diode Laser Absorption Spectroscopy (TDLAS), which achieves concentration detection by leveraging the selective absorption characteristics of methane molecules at specific wavelengths. The instrument uses a semiconductor laser to emit a narrow-linewidth near-infrared beam (typically targeting the characteristic absorption peak of methane around 1653 nm). By modulating the laser's current or temperature, the wavelength is periodically scanned within a narrow range near the methane absorption peak, ensuring precise alignment with methane's absorption lines. When the laser beam traverses the measurement area, the presence of methane gas causes its molecules to selectively absorb photons of specific wavelengths, resulting in attenuation of the laser intensity. The degree of absorption is directly proportional to methane concentration and optical path length, adhering to the Beer-Lambert Law.

2. Measurement principle

Methane molecules absorb light of specific wavelengths. ——Molecular absorption spectroscopy

The absorption of light by a transparent medium (methane gas mass) is proportional to the thickness and concentration of the gas mass. ——Bill Lambert's Law

Based on above physical principles, a beam of light with specific wavelength can be used to penetrate the leaked methane gas. Accordingly to the degree of weakening of the beam, the concentration of methane can be measured and it only responds to methane (with unique selectivity). By using a detection pool with multiple reflections, allowing the laser to repeatedly pass through the measured gas, the detection sensitivity can be significantly enhanced.

Function Features

● Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology is completely ineffective for gases other than methane, so it will not be affected by interfering gases during detection.

● The reliable measurement results can be used to accurately locate methane leak points of the buried pipelines.

● Quick response to methane leak, ultra fast reaction time.

● The leak detection mode and explosion detection mode can be flexibly selected according to different scenarios.

● The brightness and alarm values of screen are adjustable and can also be set according to the on-site conditions.

● The left side of screen displays the current detected methane value in real-time while the right side displays the entire methane detection value curve within 200 seconds in real-time, it helps provide more intuitive and real-time comparison for faster detection of the leakage points.

● The combination of touch screen and physical buttons makes the operation flexible and convenient.

● The methane leak detection values at each point can be recorded and the data can be saved as well, which makes it more convenient and intuitive to find the leak points through historical data analysis.

● The instrument air inlet, internal air path and external probe air path are all equipped with water and gas impurity filters, which can adapt to working under harsh conditions and prevent the instrument from being damaged by water and impurities.

● The rotate speed of air pump can be adjusted, and the suction pump can be individually set to turn on and off.

● Long running time of battery (12 hours).

● Intuitive navigation menu, customized parameter settings, adjustable set for alarm values.

● Lighter, smaller, and more comfortable to operate.

● Rich probe configurations. The instrument is equipped with clock probe, trolley probe, triangular goose neck probe, and telescopic needle probe, these four types are suitable for efficient gas leak detection in various scenarios such as buried pipelines, overhead pipelines, and indoor inspections. The probe can be connected and disconnected quickly through self-locking quick pneumatic plug and the self-locking telescopic rod. The length range of the self-locking telescopic rod is from 0.55 to 1.25 meters. Operators can set probe length according to their usage habits. The length of telescopic probe can also be adjusted.

● Electric vehicle based inspection and leak detection not only saves time but also be efficient and convenient, greatly reducing commuting costs and improving detection efficiency.