Patent ID: 6466691
Filing Date: 2002-10-15
Classification: G01N

Abstract:
A method for testing the reliability of a testing apparatus which checks multiple objects of the same type for one set feature, the method comprising the steps of: generating a feature signal for each object; checking the feature signal for fulfillment of a first condition; deriving a test signal from the feature signals of a plurality of objects of a common type; and checking the test signal for fulfillment of a second condition in order to test the reliability of the testing apparatus, wherein the step of checking the test signal includes comparing the test signal with a reference value, and wherein the test signal is an average of the feature signals of several objects, the reference value is a value of the feature signal to be expected for defect-free objects, and wherein a permitted deviation of the test signal from the reference value (second condition) is smaller than a deviation at which the first condition is fulfilled for an individual object.