Water vapour absorption spectroscopy in a simulated helicopter exhaust using vertical-cavity surface-emitting lasers

Abstract

This paper presents the results of water vapour spectroscopy with a vertical-cavity surface-emitting laser using tunable diode laser absorption spectroscopy. The sensor system is the first open-path, industrial sensor to detect water vapour in the 950 nm region. Testing was conducted to determine path-averaged temperature and water vapour concentration in the exhaust of the Defence Science and Technology Organisation's infrared suppression facility. The design of the sensor system and results of the data analysis are presented and compared with thermocouple measurements. Show more