Development of a High Flux Conduction Calibration Apparatus.
Development of a High Flux Conduction Calibration
Apparatus.
(626 K)
Grosshandler, W. L.; Blackburn, D.
NIST SP 971; August 2001.
NIST SP 971: "Collected Reports and Publications by the
National Institute of Standards and Technology on Heat
Flux Gage Calibration and Usage." AND American
Society of Mechanical Engineers (ASME) Heat Transfer
Division. Proceedings. Volume 3. HTD-Vol. 353. June
16-21, 1997, Dallas, TX, 153-158 pp, 2001.
Available from:
For More Information on NIST SP 971 visit: WEBSITE:
http://www.bfrl.nist.gov/866/heatflux/index.htm
Keywords:
calibration; heat flux; transducers
Abstract:
A new conduction calibration apparatus has been designed
to deliver heat fluxes up to a maximum of 100 kW/m2
with an established goal of + 5% precision. This system
will provide a close to purely diffusive (as opposed to
radiative) heat flux boundary condition and, when
compared to the gauge's response in the National
Institute of Standards and Technology (NIST) radiative
calibration facility, act as a check on the sensitivity
of a heat flux gauge to the mode of heat transfer. A
platinum-plated copper block heated electrically with 2
kW power is designed to produce uniform temperatures up
to 750 K across its face. A cold plate will be
maintained around 290 K through pool boiling using a
liquid refrigerant and a remote condenser. A 1 mm wide
helium filled gap between the hot plate and the sensing
surface of a cooled heat flux gauge will provide the
high conductive fluxes desired (while limiting radiation
to a few per cent and avoiding the uncertainties
associated with contact resistance). Detailed numerical
modeling of the device is being used to identify
limitations and evaluate alternatives in the design, and
to analyze the level of uncertainty associated with the
facility. A description of the apparatus and the
results of preliminary modeling are reported.
