Luminaire output checked with a lux meter on a desk

If the specification requires luminous flux but acceptance measures desk illuminance, different quantities are being compared. Height, optics and room reflections affect readings. Preserve layout and settings before replacement to check product performance separately from the installed lighting system.

What needs to be clarified

Check whether the method measures the specified delivery parameter, examining luminaires and installation while distinguishing product flux from work-surface illuminance against clear technical requirements.

Materials to prepare

Specification and delivered model’s photometric data
Luminaires identified by lot, driver and diffuser
Installation diagram and measurements with points, heights and instrument

What to compare

Clarify whether the requirement concerns a complete luminaire or a light source. Record voltage, dimming and stabilisation conditions. Repeat illuminance on an agreed grid with ambient light accounted for; select a separate suitable flux test. Keep results distinct, link them to examined units and justify sampling before extending findings to the delivery.

Possible outcome of the analysis

A technical report may separate product and installation findings, compare requirements and list parameters the original acceptance record did not actually measure for the delivery.

Limits of the conclusions

Lux at one point cannot replace lumens. The report determines neither acceptance legality nor penalties; technical lot assessment needs agreed criteria, test conditions and justified sampling.