Thermal luminescence sensor for ground-path contamination detection

Autor:	Michael V. Talbard, David J. Owens, Irving F. Barditch, Pascal I. Lim, Erik S. Roese, Arthur H. Carrieri
Rok vydání:	1999
Předmět:	Materials science Infrared business.industry Materials Science (miscellaneous) Industrial and Manufacturing Engineering Temperature gradient Optics Thermal radiation Thermal Irradiation Wetting Business and International Management Luminescence business Beam (structure)
Zdroj:	Applied Optics. 38:5880
ISSN:	1539-4522 0003-6935
Popis:	A standoff method of detecting liquids on terrestrial and synthetic landscapes is presented. The interstitial liquid layers are identified through their unique molecular vibration modes in the 7.14-14.29-microm middle infrared (fingerprint) region of liberated thermal luminescence. Several seconds of 2.45-GHz beam exposure at 1.5 W cm(-1) is sufficient for detecting polydimethyl siloxane lightly wetting the soil through its fundamental Si-CH3 and Si-O-Si stretching modes in the fingerprint region. A detection window of thermal opportunity opens as the surface attains maximum thermal gradient following irradiation by the microwave beam. The contaminant is revealed inside this window by means of a simple difference-spectrum measurement. Our goal is to reduce the time needed for optimum detection of the contaminant's thermal spectrum to a subsecond exposure from a limited intensity beam.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::521df25f9fc6f673a4bf2787bf738bfb https://doi.org/10.1364/ao.38.005880 Zobrazit plný text záznamu