> here were two red and two green lamps. These are a go-no/go set for parametric failures such as continuity and leakage, and a second pair of Red/Green lamps f

> here were two red and two green lamps. These are a go-no/go set for parametric failures such as continuity and leakage, and a second pair of Red/Green lamps for functional failures. Interesting idea to have separate parametric and functional test indicators. I've made a few custom production test setups in the past years (nothing as nearly as complicated as the one described here) and always went with the greatest simplicity possible - start button and a single red/green go/no go, exactly to avoid the kind of problem described later in the article. I can see why they would do that though. When reviewing test runs, it's always the parametric tests that give the most false-positives. If a parametric test fails, the part functions as intended, but some measured parameters are outside of the designed range. Parametric failures are often not failures in the parts themselves, but failures in the test procedure (e.g. bad connections to test points due to dirt or worn out contacts in the fixture, etc.). A separate indicator for parametric failure would give the operator an early indicator that excessive failures might be false positives and re-test the parts, or clean or exchange the test fixture.