IPC TM-650 1.8A

Abstract

Tests performed on presumably identical samples under seemingly identical conditions do not always yield identical results. This is due to errors inherent in every measurement or evaluation. During the development of a new test procedure or use of an existing test procedure, this variability must be understood and precautions taken to ensure that it is controlled to within necessary limits. Performance of this test method will help to estimate measurement error and troubleshoot causes of measurement variability. Use of this test method will provide some evidence that a new test procedure is suitable for use when submitted for review, or an existing test procedure is capable of measuring the applicable parameter. This method provides a standard procedure for determining the precision of a test method involving binary data or tests that result in two outcomes. These include evaluations where the results are recorded as pass/fail or go/no-go. Examples include solderability tests and visual inspections. This method helps to estimate how often the disposition is performed correctly. This method is not useful for measurements which result in variables data, or where more than three repeated measurements or more than ten testers are used. These situations are covered under other methods (see 6.1).