working photometric standard
tertiary photometric standard
device calibrated by reference to a secondary photometric standard and typically used, on a day-to-day basis, for photometric measurements
Note 1 to entry: Working photometric standards are typically photometers or light sources.
Note 2 to entry: This entry was numbered 845-05-03 in IEC 60050-845:1987.
Note 3 to entry: This entry was numbered 17-1442 in CIE S 017:2011.