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What is gage calibration?

As described in Section 1, an ultrasonic gage reads the thickness of a test piece by very precisely timing echoes. In order to turn these time measurements into thickness measurements, the gage must be programmed with the speed of sound in the test material as well as any necessary zero offset that is required by the instrument, transducer type, or echo shape. This process is commonly referred to as gage calibration. The accuracy of any ultrasonic measurement is only as good as the accuracy and care with which this calibration has been performed. Incorrect calibration will result in inaccurate thickness readings. Fortunately, calibration is usually a simple process.

A number of different calibrations for different materials and transducers can be stored in the gage and quickly recalled. It is very important to remember that a new calibration must be performed, or an appropriate programmed calibration be recalled, whenever the test material or transducer is changed, or if the temperature of the test material changes significantly.. Additionally, periodic checks with samples of known thickness are recommended to verify that the gage is operating properly, especially in critical applications.

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Velocity and Zero Calibration >>