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Design and Uncertainty Analysis of a Second-Generation Convective Heat Flux Calibration Facility



David G. Holmberg, C A. Womeldorf, William L. Grosshandler


The National Institute of Standards nad Technology has developed a convective heat flux facility to allow calibration of heat flux sensors. The facility consists of a small wind tunnel that produces a two-dimensional laminar boundary layer across a heatred isothermal copper plate. Sensors are mountd flush in the copper plate alongside a reference to measure the heat leaving the plate. Convective calibrations up to 5 kW/m2 are possible. Sensor output is compared with the reference value, and contrasted with a standard radiation calibration. Recognizing that many sensors are used in mixed radiation and convection environment, this facility provides a unique opportunity to assess a sensor's convective response. This report describes a second-generation heated plate and provides an analysis of the system uncertainty. Redundand references, imnproved sensor heating and mounting, improved reference isolation, and a minimized radiation component has reduced the combined relative expanded uncertainty of the reference to +2.5%. The benefits of an embedded temperature sensor in the heat flux sensor are described. The facility is available for comparative calibrations and for heat transfer studies by indivdual researchers.


calibration, convection, radiation, heat flux, standards, uncertainty, heat flux gauge


Holmberg, D. , Womeldorf, C. and Grosshandler, W. (1999), Design and Uncertainty Analysis of a Second-Generation Convective Heat Flux Calibration Facility, Other, National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 13, 2024)


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Created January 1, 1999, Updated February 19, 2017