NATA class of test 1.64.02

Illuminance meters can be calibrated for

Responsivity  CIE Sources A and C

The results are normally given in the form of a correction factor rather than adjusting the readout.

Up to 10 000 lux with a least uncertainty of 1.2%

>10 000 to 50 000 (not part of a NATA endorsed report) with a least uncertainty of ?%

Cosine correction

Spectral responsivity (broadband method)

Based on sources calibrated by the National Measurement Institute, Australia.