- Author
-
Zarr, R. R.
- Title
- Control Stability of a Heat-Flow-Meter Apparatus.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
-
Journal of Thermal Insulation and Building Environments,
Vol. 18,
116-127,
October 1994
- Book or Conf
- American Society for Testing and Materials. Measurement Errors and Methods of Calibration of Heat-Flow-Meter Apparatus. ASTM C-16 Workshop. April 9, 1994,
Williamsburg, VA,
1994
- Keywords
-
building technology
|
heat flow meter
|
control stability
|
fibrous glass
|
heat transmission
|
steady state
- Abstract
- Calibration measurements of a commercial heat-flow-meter apparatus are presented. The apparatus has been calibrated using the same specimen of high-density fibrous-glass board over a period of four years, from 1989 to 1993. A total of seventy-three tests have been conducted generally, at ambient conditions of 24 deg C with a moderate temperature difference of either 15, 22 or 27 deg C across the specimen. Variations within a set of data for each test have been examined to verify underlying assumptions of randomness, normal frequency distribution of errors, repeatability, and stability of the data. Variations between test data indicate a small drift, on the order of one percent over four years, in the calibration factor of the apparatus. A model has been developed to describe the small drift with time. The analysis of variations between test data has also identified intermittent shifts in the precision of the calibration factor of the apparatus.