MEASURING METHOD FOR THERMAL SIZE VARIATION OF OFF-SPECIFICATION SAMPLE OF THERMOMECHANICAL MEASURING INSTRUMENT

摘要

PURPOSE:To accurately measure thermal size variation by preparing a sample to be measured by using the same material with a standard sample, equalizing total length including the sample to be measured to that of the standard sample and mounting it on a thermomechanical measuring instrument together with a spacer which is adjusted within the permissible range of the thermomechanical measuring instrument, and detecting the difference in heat expansion from the standard sample. CONSTITUTION:The spacer 11 is joined with the lower part of the sample 1 to be measured after the length l2 of the spacer is so adjusted that l1+l2 l0 and 10mm=l0=20mm under the restrictions of the measuring instrument, where l0 and l1 are the respective lengths of the standard sample 2 and the sample 1. When the spacer 11 is made of the same material as that of the standard sample 2, the heat expansion of the spacer is canceled by the equal-length part of the standard sample 2 and can be ignored. The coefficient of heat expansion of the sample is accurately determined by correcting the signal of a differential transformer for the coefficient of heat expansion of the standard sample 2.