差分模式激发光声光谱法：一种新的光声检测方案。

Differential mode excitation photoacoustic spectroscopy: a new photoacoustic detection scheme.

作者信息

Rey J M, Sigrist M W

机构信息

Laser Spectroscopy and Sensing Laboratory, Institute of Quantum Electronics, ETH Zurich, Schafmattstrasse 16, CH-8093 Zurich, Switzerland.

出版信息

Rev Sci Instrum. 2007 Jun;78(6):063104. doi: 10.1063/1.2746817.

DOI:10.1063/1.2746817

PMID:17614602

Abstract

A robust and simple gas sensor based on a novel photoacoustic scheme named "differential mode excitation photoacoustic spectroscopy (DME-PAS)" is presented. This method takes advantage of the selective excitation of two different modes in a resonant photoacoustic cell. A blackbody light source is used for simplicity in combination with optical correlation to provide a good selectivity. The frequency response of the proposed resonant cell is modeled using the extended Helmholtz resonator theory. The DME-PAS device is tested using acetone vapor and a model developed to describe its response when the gas concentration is varied. The obtained limit of detection is 25 ppm m(-1) for acetone in room air. Using DME-PAS, the derived gas concentration is affected neither by intensity fluctuations of the light source nor by any microphone drifts.

摘要

本文介绍了一种基于名为“差分模式激发光声光谱法（DME-PAS）”的新型光声方案的坚固且简单的气体传感器。该方法利用了共振光声池中两种不同模式的选择性激发。为简化起见，使用黑体光源并结合光学相关性以提供良好的选择性。使用扩展的亥姆霍兹共振器理论对所提出的共振池的频率响应进行建模。使用丙酮蒸气对DME-PAS装置进行测试，并开发了一个模型来描述当气体浓度变化时其响应。在室内空气中，丙酮的检测限为25 ppm m(-1)。使用DME-PAS，导出的气体浓度既不受光源强度波动的影响，也不受任何麦克风漂移的影响。