Laser Research Group, Physics Department and Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, Dhahran, Saudi-Arabia.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2009 Nov;44(13):1457-64. doi: 10.1080/10934520903217740.
A highly sensitive pulsed photoacoustic (PA) spectrometer with different PA cell geometries was designed and fabricated in our laboratory to determine ozone detection at ppb level. The comparative performance and merits of these custom made cells were studied. The excitation source of PA spectrometer is a nanosecond pulsed laser at 266 nm (fourth harmonic of Nd:YAG laser) and a sensitive electret microphone as a photoacoustic detector. The sensitivity optimization of the PA system with different experimental parameters including the resonant acoustic modes of the 3 PA cells was carried out for the detection of ozone. The minimum detection limit for ozone achieved under our experimental conditions, with 3 PA cells were 10, 31 and 26 ppbV for cells designated as cell # 1, cell # 2 and cell # 3, respectively. This limit of ozone detection achieved in our work is quite appreciable to be able to detect ozone under safe permissible limits and the sensitivity achieved in our case is an order of magnitude better than earlier reports using sophisticated laser system like quantum cascade laser.
我们实验室设计并制造了一种具有不同光声池结构的高灵敏度脉冲光声（PA）光谱仪，用于检测 ppb 级别的臭氧。研究了这些定制光声池的比较性能和优点。PA 光谱仪的激发源是 266nm 的纳秒脉冲激光（Nd:YAG 激光的四倍频）和作为光声探测器的灵敏驻极体麦克风。为了检测臭氧，对不同实验参数（包括 3 个 PA 池的共振声模式）的 PA 系统进行了灵敏度优化。在我们的实验条件下，使用 3 个 PA 池，对臭氧的最小检测限分别为 10、31 和 26 ppbV，分别对应于编号为 cell # 1、cell # 2 和 cell # 3 的光声池。在我们的工作中实现的臭氧检测极限是相当可观的，能够在安全允许的极限下检测臭氧，并且在我们的情况下实现的灵敏度比使用量子级联激光器等复杂激光系统的早期报告提高了一个数量级。
