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Author
Vettori, R. L. | Twilley, W. H. | Stroup, D. W.
Title
Measurement Techniques for Low Heat Flux Exposures to Fire Fighters Protective Clothing.
Coporate
National Institute of Standards and Technology, Gaithersburg, MD
Report
NIST SP 971; NISTIR 6750
August 2001; June 2001
89 p.
Book or Conf
NIST SP 971: "Collected Reports and Publications by the National Institute of Standards and Technology on Heat Flux Gage Calibration and Usage.", 2001
Keywords
protective clothing | fire fighters | heat flux | exposure | burns (injuries) | fire research | sensors | temperature measurements | test methods
Identifiers
temperature measuring instruments
Abstract
A series of experiments were conducted to identify measurement technologies that are appropriate for evaluating the thermal performance of firefighter protective clothing under low heat flux (less than or equal to 5.0 kW/m2) exposure conditions and for relatively long periods of time, up to 10 minutes. Selected sensors were tested in six different configurations and exposed to three different levels of heat flux from a gas fired radiant panel. The 6 different configurations were (1) the sensor exposed to the radiant panel with no contact with anything other than the wires transmitting the sensor output signal (2) the sensor mounted on a substrate such that the surface of the sensor is flush with the surface of the substrate and exposed to the radiant panel (3) a piece of firefighter protective clothing is placed between the sensor and the radiant panel, the sensor is touching the back of the material (4) a piece of firefighter protective clothing is placed between the sensor and the radiant panel, the sensor is placed 6 mm behind the material (5) a piece of firefighter protective clothing is placed between the sensor and the radiant panel, the sensor is mounted on the substrate and touching the back of the material (6) a piece of firefighter protective clothing is placed between the sensor and the radiant panel, the sensor is mounted on the substrate and placed 6 mm behind the material. The three levels of heat flux were 1.25 kW/m2, 2.50 kW/m2, and 5.00 kW/m2. For a given configuration, there was a considerable variation in the reported measurement between sensors. All sensors were affected by placing them on the substrate. Based on the results from this experimental series the Schmidt-Boelter total heat flux gauge was deemed the most appropriate for measuring incident heat flux. For measuring the surface temperature of a fabric, the use of a thermal pad, made of a material with a high thermal conductivity to which is attached a thermocouple with lead wires made of a material with a low thermal conductivity, may be the most appropriate.