Method and Apparatus for Calibrating a Densitometer Based Sensor for Shot Peening

Author:  RA Thompson, New York, NY
Source:  US Patent 6,142,027
Doc ID:  2000019
Year of Publication:  2000
Abstract:  
An apparatus and method are provided for calibrating a densitometer based sensor for measuring the linear density of the shot particles passing through a shot peening system to ensure that mass flow rate readings and shot velocity readings calculated therefrom are accurate. The apparatus comprises a probe having a plurality of randomly distributed particles configured to have a linear density substantially equal to the linear density of shot which the sensor should experience during operation of the shot peening system at desired parameters. The method comprises recording a sensor reading of the particles of the probe with the probe inserted in the sensor, removing the probe, dividing the known linear particle density of the probe by the sensor output to obtain the sensor calibration constant and multiplying each subsequent sensor output taken during normal operation of the shot peening system by the calibration constant to obtain an accurate instantaneous linear density reading of the shot traveling through the shot peening system.