Biogas Analyzer and System

Tunable diode laser spectroscopy (TDLAS) is a narrowband laser-based technology. TDLAS methane detector mainly consists of a laser light source, gas chamber and photodiode.

The wavelength is tuned to the absorption optical spectrum of the target gas through periodic modulation of the input current. After targeted gas absorption, the remaining laser light will arrive at the photodiode which will be detected. The absorption is calculated according to the Beer-Lambert law. The amount of absorption relies on the optical path length in the gas chamber and the absorption coefficient of the target gas.

Cubic TDLAS technology adopts a long laser light path by multiple reflections, enabling low range, superior-low detection limit,  and high-resolution quantitative measurement.

Ultraviolet Differential Optical Absorption Spectroscopy (UV-DOAS) is a broadband ultraviolet light-based technology. The UV light source, gas chamber, and spectrometer/photodetector comprise the primary components of a UV-DOAS sensor.

The broadband UV light passes through the sample gas, where specific wavelengths are absorbed by the target gas molecules. The spectrometer detects the transmitted light intensity across the spectrum after absorption. The Beer-Lambert law is employed to determine the absorption. The absorption coefficient of the target gas at specific wavelengths and the optical path length in the gas chamber determine the extent of absorption.

UV-DOAS technology utilizes a calibrated absorbance-concentration curve established via spectral analysis of the transmitted spectrum. This facilitates the real-time calculation of target gas concentration based on the measured absorbance, enabling simultaneous multi-component detection.