Calibration Apparatus and Method for Shot Blasting Intensity Measurement

Author:  Jack Champaigne, South Bend, IN
Source:  US Patent 5,780,714
Doc ID:  1998023
Year of Publication:  1998
Abstract:  
A calibration apparatus and method for shot blast intensity measuring gages uses a calibration block which is placed upon the measuring surface of the gage. The calibration block has a zero datum surface with a notch cut into the zero datum surface at a predetermined calibration depth. The measuring block is sufficiently shorter than the test strips such that the measuring block can be shifted between a zero datum reference position in which the flat surface is supported over the plunger which operates the read-out display. The measurement block is then shifted relative to the measurement surface to a second position in which the plunger or feeler of the display engages the notch to permit a calibration reading to be taken. Since the measurement block is supported on the same surface when both the zero datum measurement and the calibration measurement are taken accuracy is improved since it is assured that the calibration measurement is referenced from the same flat surface from which the zero datum measurement is taken.