Accession Number : ADA187885

Title :   Evaluation of a Temperature Remote Sensing Technique.

Descriptive Note : Technical memo.,

Corporate Author : JOHNS HOPKINS UNIV LAUREL MD APPLIED PHYSICS LAB

Personal Author(s) : Gearhart, S A ; Thomas, M E

PDF Url : ADA187885

Report Date : Jul 1987

Pagination or Media Count : 29

Abstract : A noninvasive technique for measuring temperature in hot gases is evaluated as an alternative to conventional mechanical probing techniques. The technique uses a diode laser spectrometer to measure the line-center absorption coefficient ratio of two absorption lines that originate from different vibrational energy levels of the same absorbing species. The temperature is calculated without knowledge of the pressure, absorber concentration, or optical path length. A previous study demonstrated temperature measurements at about 200K at atmospheric pressure. The results of this evaluation suggest that the technique is also applicable for temperatures as low as 400 K and at pressures well below 1 atm. Keywords: Temperature measuring instruments; Combustion diagnostics; Laser absorption techniques.

Descriptors :   *ABSORPTION SPECTRA, *COMBUSTION, *REMOTE DETECTORS, *TEMPERATURE MEASURING INSTRUMENTS, *LASER APPLICATIONS, *COLLISION BROADENING, DIAGNOSIS(GENERAL), HOT GASES, LENGTH, LINE SPECTRA, MEASUREMENT, MOLECULAR ENERGY LEVELS, MOLECULAR VIBRATION, OPTICS, PATHS, SPECTROMETERS, THERMAL PROPERTIES, LASER BEAMS, SEMICONDUCTOR LASERS, SEMICONDUCTOR DIODES

Subject Categories : Test Facilities, Equipment and Methods
      Lasers and Masers
      Combustion and Ignition
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE