Evaluation and elimination of errors in impact testing machine

Abstract

To determine the confidence of the test results, it is necessary to evaluate the main factors contributing to the uncertainty in Charpy impact measurement. These factors are: the uncertainty of reference force and length measuring devices and its long term instability, machine resolution, rated energy error, indicated energy error, losses due to the drag of the pointer, friction losses in the bearing and air resistance and other geometric para-meters. In this study the calibration process is based on the relevant Indian and international standard is explained. Most of the uncertainty elements are identified and directly verified. Other elements not be directly verified are analyzed or assessed using available information.