Application of a miniaturized photoacoustic cell for high-sensitivity laser detection of ammonia in gas media

TL;DR

This paper introduces a miniaturized photoacoustic cell with high sensitivity for detecting ammonia gas using a CO2 laser, emphasizing design optimization to reduce background noise and achieve low detection limits.

Contribution

The study presents a novel small-volume photoacoustic cell optimized for ammonia detection, demonstrating high sensitivity and low detection limits with a specific laser setup.

Findings

Minimal detectable absorption of ~5.1×10^(-8) cm^(-1) W Hz^(-1/2)

Effective reduction of background signal through cell shape design

Successful detection of ammonia in nitrogen flow

Abstract

We present a photoacoustic resonant cell, the internal volume of which is ~ 0.5 cm^3. The cavity shape of the cell is so adapted in order to minimize the background signal arising due to absorption of laser beam in the cell windows. An experimental setup, measurement procedure and design of the cell are described. Results of detection of ammonia in nitrogen flow with the help of a CO2-laser are represented. The minimal detectable absorption for the cell is estimated in the experiment to be ~ 5.1 10^(-8) cm^(-1) W Hz^(-1/2)