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General Attributes:

Thorlabs QEPAS-CH4 very good price

QEPAS-CH4

QEPAS System for Methane Detection

• Complete Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) System
• Designed to Measure Methane Concentrations from <0.5 ppm to 10 000 ppm
• Calibrated for Synthetic Air and Nitrogen Gas Matrixes with 1000 ppm to 32 000 ppm Water Vapor
• System Designed for Benchtop or 19" Rack Mount

Features

• Detects Methane Concentrations from <0.5 ppm to 10 000 ppm*
• Calibrated for Use in Synthetic Air and Nitrogen Gas Matrixes
• Accurate Measurements with Gas Matrix Water Concentrations from 1000 ppm to 32 000 ppm 
• Small Gas Sample Volume of 20 cm³
• Simple, "All-in-a-Box" Design
• Included Software with Intuitive GUI Interface 

Applications

• Oil and Gas Research
• Pipeline Leakage Detection
• Chemical Analysis

• Trace Gas Sensing
• Environmental Monitoring
• Atmospheric Chemistry

Thorlabs' Quartz-Enhanced Photoacoustic Spectroscopy (QEPAS) Sensor is a compact and complete system for methane (CH₄) detection. It features a robust design that does not require any user alignment and is ready to use out-of-the-box; by simply connecting the target gas sample to the QEPAS-CH4 sensor and using our QEPAS Software, methane concentrations from <0.5 ppm to 10 000 ppm* can be measured with an accuracy of ±5% and <0.17 ppm signal noise (at concentrations <5 ppm).

The QEPAS-CH4 sensor features an "all-in-a-box" design and is equipped with all necessary components for methane detection. The test gas is connected to the front panel of the sensor, and internal pressure and flow controllers direct the gas to our ADM01 Acoustic Detection Module. An internal laser centered at the CH₄ absorption line excites the target gas molecules, and the quartz tuning fork (QTF) of the ADM01 module detects the pressure waves as the molecules relax. The amplitude of the QTF signal, which is directly proportional to the methane concentration, is measured by an internal DAQ-card and the concentration is clearly displayed in the QEPAS Software. For more information on the operating principles of QEPAS, please see the QEPAS tab.

The signal of a QEPAS measurement is strongly dependent on the amount of water vapor in the gas matrix. Collision with water molecules provides an additional relaxation pathway for the excited target molecules, thereby increasing the QEPAS signal. The QEPAS-CH4 sensor is calibrated to adjust the QEPAS signal for the presence of water using a built-in water sensor to continuously measure the concentration in real-time. This allows accurate and precise methane detection measurements to be performed in the presence of water with concentrations ranging from 1000 ppm to 32 000 ppm. Each sensor comes with a specification sheet that includes a thorough statistical analysis of the QEPAS-CH4 sensor performance under a wide range of experimental conditions.