A Guard-Band Strategy for False-Accept Management
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When performing a calibration, the risk of incorrectly declaring a device as in-tolerance (false-accept risk) is dependent upon several factors. Those factors include the specified tolerance limit, guardband, the calibration process uncertainty and the a priori probability that the device is intolerance. A good estimate of the a priori probability may be difficult to obtain. Historical or device population information for estimating the a priori probability may not be readily available and may not represent the specific device under test.
A common strategy for managing measurement decision risk is to choose a guard-band that results in the desired false-accept risk given the tolerance limit, the calibration process uncertainty and the a priori probability. This paper presents a guard-band strategy for managing false-accept risk with only limited knowledge of the a priori probability that a device is intolerance.