A LabVIEW‐based TDLAS methane detection system using a wavelet denoising method

Abstract

A methane detection system based on tunable diode laser absorption spectroscopy (TDLAS) using LabVIEW platform was demonstrated. To suppress the noise interference in the system, a wavelet denoising method was studied and experiments with different parameters were carried out. With the threshold of Hard, the wavelet basis of Coif5 and the rule of Heursure, high frequency noises of the sensor can be effectively decreased with the harmonic amplitude increased. Experiments showed that, the 1σ minimum detection limit (MDL) was 23.68 ppbv (part per billion of volume) with an integration time of 300 s.

Analyzing the Applicability of ML Powered Microwave Sensor for UAV Based CH4 Sensing

“…MATLAB-Wavelet analyzer and denoiser toolsets are utilized for both low frequency approximation output (A) and high frequency details (D) measurement. Inspired from the [22] author's work, Coiflet (Coif) wavelet transform was used in this study. A case-to-case analyses has been conducted using Coif wavelet with subclasses one to five and approximation/detail levels ranging from one to five as illustrated in Fig.…”

Ppb‐level CO2 sensor based on a miniature multipass cell with eight‐petaled spot pattern

“…Among these, optical sensors stand out for their superior sensitivity and selectivity. Prominent optical gas sensing technologies include nondispersive infrared (NDIR), 7,8 cavity ring‐down spectroscopy (CRDS), 9 photoacoustic spectroscopy (PAS), 10–16 and tunable diode laser absorption spectroscopy (TDLAS) 17–22 . NDIR sensors are particularly favored for their affordability and compact size.…”

Oxygen detection based on Faraday modulation spectroscopy and wavelength modulation spectroscopy: A comparison

“…Faraday modulation spectroscopy (FAMOS) and wavelength modulation spectroscopy (WMS) are two optical‐based physical methods which is effective for O 2 detection. The characteristics and applications of WMS has been introduced by many researchers 11–13 . FAMOS, develop from magnetic rotation spectroscopy (MRS), is relies on the Faraday effect of paramagnetic molecular transitions.…”

“…The characteristics and applications of WMS has been introduced by many researchers. [11][12][13] FAMOS, develop from magnetic rotation spectroscopy (MRS), is relies on the Faraday effect of paramagnetic molecular transitions. As MRS is only sensitive to paramagnetic molecules, interferences from abundant atmospheric species such as water or carbon dioxide can be effectively avoided.…”