Uncertainty evaluation of luminometer measurements in testing laboratories

Zhu Aiju, a professional from Taizhou Metrology and Testing Technology Research Center, conducted an experimental study on the uncertainty of the measurement value of the illuminance meter in the testing laboratory, and wrote this article "Evaluation of the Uncertainty of the Measurement Value of the Luxmeter in the Testing Laboratory". The experiment is to measure the illuminance with an illuminance meter at a distance of 2.5m from the two lamp tubes, and record the fluctuation of the power supply voltage to ensure that the measurement conditions are relatively unchanged, so as to evaluate the uncertainty of the measured value of the illuminance meter .

Experimental measurement basis: "Evaluation and Expression of Measurement Uncertainty" (JJF1059. 1-2013)

Measurement environment: temperature 20 ± 10 ℃, relative humidity ≤ 75%RH.

Measuring instrument: illuminance meter testo540; measuring range is (0 ~ 99999) Lux; uncertainty or accuracy or maximum allowable error is ± 3% of the reference value; resolution is 1 Lux (0 ~ 19999) Lux, 10 Lux ( other ranges).

Tested objects: indoor double-ended straight tube fluorescent lamps, 2 pcs

Measurement method: According to the method stipulated in the standard "Lighting Measurement Method" (GB/T5700-2008 ), measure the illuminance with an illuminance meter directly below the two lamp tubes and at a distance of 2.5m from the lamp tubes, and record the fluctuation of the power supply voltage to ensure the measurement The conditions are relatively unchanged.

Experimental results: The relative expanded uncertainty of the measured value of the illuminometer is Urel=5. 8% ( k=2 )  .