Research on Non-contact Calibration Method of Extensometer Calibrator Indication Error

The calibration method of indication error of the extenso meter calibrator was studied to solve the problems of complicated operation, low efficiency and relying on operating experience in the current calibration using the gauge block method. A method based on laser interference principle was used to calibrate the indication error of the extenso meter calibrator in a non-contact manner, and a comparative experiment was applied. The results of experiment and measurement uncertainty analysis shows that the non-linear error of measurement data obtained by laser interference method is -0.003%, and the expanded measurement uncertainty under 1/3mm can reach 0.095μm(k = 2), which can meet the requirements of the regulations for calibration of the indication error of the extensometer calibrator.