摘要 |
A noncontact thickness gauge system for measuring the thickness of a material is disclosed which includes a source of penetrating radiation, a radiation detector for detecting the amount of radiation received from the radiation source where the level of received radiation is a function of the radiation absorption characteristics and thickness of the material located in the radiation path, a memory for storing the output signals of the detector and curve-defining parameters for a plurality of calibration curves which correspond to respective ranges of thickness values, and a processor for processing the various signals and curve-defining parameters to determine the thickness of the material in the radiation path. The calibration curves are quadratic and are defined by at least three calibration points. Measurements using the radiation thickness gauge system are done after precalibrating the gauge system to obtain a plurality of calibration curves, storing the calibration curves in the memory, providing the signals representative of the nominal thickness and the alloy compensation coefficient for the material to be measured, selecting the calibration curve corresponding to a particular thickness range, compensating the calibration curve of the selected range for drift, inserting the material to be measured into the radiation path and then processing the output signal of the detecting means with the compensated calibration curve to determine the apparent thickness of the material.
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