Real-Time Suppressant Concentration Measurement (NIST SP 890)

Published

November 1, 1995

Author(s)

William M. Pitts, George W. Mulholland, B D. Breuel, Erik L. Johnsson, S Chung, Richard H. Harris Jr., D E. Hess

Abstract

The development and testing of two approaches for recording real-time measurements (millisecond time resolution) of concentration for halon alternatives are summarized. Discussions of the background necessary to understand their operation is included. The first instrument is a combined aspirated hot-film/cold-wire probe which is calibrated to record both temperature and concentration. The second is a specially developed instrument based on infrared absorption near 8.5 mm which has been dubbed the Differential InfraRed Rapid Agent Concentration Sensor (DIRRACS). A series of tests of the instruments in the full-scale dry-bay test facility at Wright-Patterson AFB is summarized. The characteristics of the current devices used to measure halon 1301 concentrations - the Statham analyzer and Halonyzer - are reviewed. The final section contains a literature review assessing other potential techniques for making the required concentration measurements.

Citation

Special Publication (NIST SP) - 890

Report Number

890

NIST Pub Series

Special Publication (NIST SP)

Pub Type

NIST Pubs

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Keywords

fire suppression, aircraft engines, nacelle fires, simulation, halon 1301, halon alternatives, aspirated hot films, cold wires, concentration fluctuations, concentration measurement, infrared detectors, infrared absorption, temperature measurements

Citation

Pitts, W. , Mulholland, G. , Breuel, B. , Johnsson, E. , Chung, S. , Harris, R. and Hess, D. (1995), Real-Time Suppressant Concentration Measurement (NIST SP 890), Special Publication (NIST SP), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=911760 (Accessed October 22, 2025)