Measurement of Kinetic Energy of Shot at Shot Peening (I)

Characteristics of Apparatus

Abstract

A kinetic energy of shot projected is obtained from the measurements of the number, diameter, speed, etc. of shot as an electric pulse. An apparatus is designed and consists of a condenser type converter, a microcapacity circuit, an amplifier, a pulse amplitude selector, a time signal generator, a pulse duration selector and a counting circuit. The grid voltage-plate ampere characteristics of the gated beam tube, 6 BN 6, is applied to these selectors and a time signal generator.
When the steel ball of 1.04.0mm in diameter passes vertically between the condenser plates of the converter, the output pulse is generated. This pulse amlitude is proportional to the 3.2 th power of the diameter of the ball and the reciprocal of this pulse duration is equal to the falling velocity. A pulse amplitude selector and a pulse duration selector discriminate the pulse of higher amplitude and longer duration than the predetermined values respectively. Thus the output pulse is counted with the relative error of ±8 %.