A compact portable photoacoustic spectroscopy sensor for multiple trace gas detection

Abstract

A compact, highly sensitive, and cost-effective photoacoustic spectroscopic sensor for multiple trace gas detection was reported with a self-designed compact distributed feedback laser array and a 2-channel dual phase field programmable gate array based digital lock-in amplifier, only twentieth in size and weight of the commercial instruments. The capability of the portable sensor was verified by measuring CH4 and C2H2 simultaneously. With an integrated nonlocal means algorithm denoising, noise-equivalent concentrations were achieved as 6.89 ppb for CH4 and 2.74 ppb for C2H2, respectively, corresponding to a normalized noise equivalent absorption coefficient of 1.1 × 10−10 cm−1 W/Hz−1/2, a 79 folds higher than the original data. The results demonstrate that the developed minimized sensor has the potential for sensitive and portable measurement of multiple trace gases.