An Explanation of Fail Verification

Fail Verification is a system used to confirm that an electrical safety tester is functioning properly and will detect failures in the Device Under Test (DUT). There may be more familiarity with the "external verification box," which has been available on the market for many years. While these verification boxes have served their intended purpose, they do represent an extra piece of equipment that must be hooked up to the safety tester to perform the test. Mechanical in nature, these verification boxes were needed because many of the available safety testers on the market were of the older analog style design. Today's safety testers contain microprocessor-controlled technology and software-driven-circuits that allow for verification to be built-in to the instrument itself. These not only eliminate an extra piece of mechanical equipment and save cost, but the tests themselves are easier and safer to perform since there is nothing external to hook up. The internal verification system determines whether or not the safety tester will detect a failure condition in a DUT. Associated Research's VERI-CHEK® system is an example of an internal verification system. Various safety agencies have required manufacturers to perform this test, ensuring that unsafe products are not shipped because the test instrument itself is malfunctioning. While it is always possible for a component failure to cause the instrument to malfunction, there are other conditions that can cause inaccurate results in electrical safety testing.