학술논문

Comparison of Metrological Techniques for Charpy Impact Machine Verification
Document Type
stp-paper
Author
Source
Charpy Impact Test: Factors and Variables, Jan 1990, Vol. 1990, No. 1072, pp. 20-34.
Subject
impact machines
Charpy machines
friction loss
period of oscillation
clinometer
THE PENDULUM-IMPACT MACHINE
Language
English
Abstract
Different measuring techniques were used to determine some of the specified characteristics of nine Charpy impact machines. In general, the techniques used were specified or recommended by one or more national standards. For example, the elevation of a raised pendulum was determined by direct measurement with a ruler and also by calculation from the measured angle of the pendulum rod. Both methods gave equal values with about the same reproducibility. On the other hand, significant differences were found when the friction loss in the pendulum was measured by a single swing and by multiple, successive swings. Significant differences in the period of oscillation were also found when the maximum angle of swing was 15 degrees as compared with 5 degrees. Both values were specified as permitted maximums in some national standards.