An Analysis and Design of a Linear Guarded Cut-Bar Apparatus for Thermal Conductivity Measurements
Abstract
A quantitative analysis of the Cut-Bar method of measuring the thermal conductivity of solids is performed. The mathematical model, which corrects for the difference in heat flux in the specimen and reference standard, is that of the two dimensional steady heat conduction equation applied to an annulus of insulation. The solution is presented in detail and found to be comprised of two physically distinct parts, a conductivity factor and a geometrical factor. A number of charts and graphs are presented for clarification as to the nature and magnitude the relative sizes of the various components will have on the accuracy over different conductivity ranges. The complexity of the geometrical factor required digital computer programs which are included. Reference is made to a similar study, performed by researchers at the National Bureau of Standards. It is found that the differences in the guard temperature distribution results in a substantial change in the geometrical factor.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 31, 1968
- Accession Number
- AD0665789
Entities
People
- David A. Didion
Organizations
- The Catholic University of America