SI base unit for
luminous intensity (symbol:
). The

is the
luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency

and that has a
radiant intensity in that direction of
(

)

per

.
Source:
PAC, 1996, 68, 957
(Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations
1996))
on page 964