CREEPAGE TEST OF SR-4 STRAIN GAGES UNDER HIGH STEADY STATE STRAINS

摘要

This memorandum compares the stability of the SR-4 paper base gages. (A-7 and A-14) with the stability of the SR-4 bakelite base gage, (AB-14) under high steady strain. The paper base gages have a tendency to creep when subjected to steady strains and reduce the stress in the wire grid of the strain gage. The SR-4 bake¬lite base gage is quite stable except for a small creepage during the first hour or so of applied strain. This small creepage can be materially reduced by cycling the gage between maximum expected strain and zero strain several times before starting the test.