Calibration of nondestructive birefringence fuel thermal deposit rating device. Final report, September 1987-March 1988

This documents the results of SwRI comparison of techniques for measuring the thickness of deposits formed on the surface of heated metal tubes during JFTOT testing of fuels. The techniques evaluated in this program included optical birefringence, dielectric strength, and ion milling. A fourth method involving cross sectioning and direct measurement of deposit thickness at high magnification using electron microscopy would serve as referee if wide disagreement among the three primary techniques was encountered. Considering the inherent difficulties in measuring deposits of less than 1 micrometer by any indirect approach, all three methods showed surprisingly good agreement when the data were plotted for comparison.