Method of Calibrating Gages Used In Measuring Intensity of Shot Blasting

Author:  Jack M. Champaigne
Source:  US Patent 6,289,713 B1
Doc ID:  2001001
Year of Publication:  2001
Abstract:  
A method for calibrating a gage for measuring shot blast intensity having an indication mounted on a platform adjusts the calibration of the indicator to compensate for variations of positioning of the Almen test strip supports on the platform. After verifying that the test strip supports are within tolerance by use of "go-no go" gages, the indicator is mounted on the support and calibrated by using a notch calibration block to first set the zero datum of the indicator and then to make a calibration reading of the depth of the notch. If the reading is within specifications, the notched calibration block is removed, and a calibration block having a curved surface simulating the curvature of an Almen strip to be measured by the Almen gage and having a known maximum deflection is installed on the gage and the indicator used to measure the deflection. If the measured deflection is within tolerance limits of the known actual deflection, the indicator is recalibrated to read the actual deflection. By calibrating gages in this manner, all gages at a facility which have been calibrated by using the same calibration blocks will read the same, thus eliminating inconsistencies between gages.