How does a fixture reach a photometric pass?
The flow from the required areas and limits to a signed result, with a retest route when a fixture falls short.
The photometric compliance flow takes the required areas and colour limits from the standard, sets up with calibrated equipment and correct alignment, measures intensity on the grid and chromaticity, and overlays the results on the requirements. A fixture passes only if intensity, colour and beam all hold; a pass on intensity alone is not a pass.
After a fail, the alignment and test set-up are checked first, then the cause is traced, corrected and the test repeated from set-up, with every retest recorded. The limit is never moved to fit the result. After a pass, the report is signed and filed with the compliance matrix.
Frequently Asked Questions
Q1What is the photometric compliance flow?
It is the route from the requirement to a signed result. The required areas and colour limits are taken from the standard, the test is set up with calibrated equipment, intensity and colour are measured, the results are compared with the requirements, and a pass or fail decision is made and recorded.
Q2Where do the required values come from?
From the applicable standard and the contract or specification that cites it, not from the test laboratory or the manufacturer's preference. Confirm the current edition with the authority or client before the test, and write the source on the report.
Q3What does a pass need?
Intensity, colour and beam must all hold. The intensity must meet the required value at each point or area the standard names (some limits are averages over an area, not single points), the chromaticity must sit inside its limit box, and the beam must cover the required area and be aimed correctly. A fixture that passes on intensity but fails on colour does not pass. Any tolerance or measurement uncertainty is applied exactly as the standard or contract states, not by judgement.
Q4What should be done after a fail?
Check the alignment and the test set-up first, because either can distort the result. Then trace the cause, correct it, and repeat the test from the set-up step. Record the failed result and the retest. The limit is never changed to suit the result. If a result outside the limit is to be accepted at all, that needs a formal, recorded concession from the authority or client.
Q5What goes into the final record?
The requirement and its source, the fixture identity and supply current, the set-up and instrument details including calibration, the measured results, the comparison, the decision, any retests, and the signatures. File it with the compliance matrix so the fixture's compliance can be shown later.
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