Irradiance

Luminance

NATA class of test 1.63.02

Luminance meters can be calibrated for

Responsivity  CIE Sources A and C

The results are typically given in the form of a correction factor rather than adjusting the readout.  A Photo Research Spectra Pritchard PR-1980A can be adjusted and a PR-880 can be programmed.

From 0.1 cd.m-2 with a least uncertainty of 0.01 cd.m-2  or 1.4% (whichever is the greater)

Extent of sensitive area

Spectral responsivity (broadband method)

Based on sources calibrated by the National Measurement Institute, Australia and surfaces calibrated by the National Research Council of Canada and the National Physical Laboratory.