Accession Number:

AD0292255

Title:

AN ASSESSMENT OF THE ERRORS INVOLVED IN THICK-FILM HEAT TRANSFER MEASUREMENTS

Descriptive Note:

Corporate Author:

BOEING CO SEATTLE WASH

Personal Author(s):

Report Date:

1962-12-05

Pagination or Media Count:

1.0

Abstract:

A study of the calibration procedure for the thick-film gage constant P.ClR alpha sub o was made to establish calibration acuracy. It was found that the R alpha sub o determination by the water-bath method was uncertain within 8 due to Joule heating effects. Analysis of the Joule heating effects led to improvements in the measurement technique, which reduced the R alpha sub o error to 0.5. The error associated with the manufacturers values of PAND C at a reference temperature of 0 C was found to be 1. For gage temperatures above 0 C no recommended values are given. Another large uncertainty is in the measurement of l which is fixed at 10 with current measurement techniques. This error, in fact, is the predominant contribution to over-all calibration error at the reference gage temperature 0 C which is 10. It was found that relative heat transfer measurements under uniform flow conditions in the shock tube can be obtained within an accuracy of 4. Thus, for gage temperature variation in the vicinity of 0 C, the absolute heat transfer measuring accuracy by virtue of the 10 calibration error, is about 11. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE