Filter
Top Products
– 47 –
HD 9021/Cd
Probe for measuring LUMINANCE, measuring range from 0 to 1999x10
3
candles/cm
2
. Measuring angle 6° with opening surface 25 mm. CIE filter for
correction according to the human eye.
- The CANDLE (cd) is the light intensity in a specific direction of a source
that emits monochrome radiation at a frequency of 540x10
12
Hz and who-
se energetic intensity in that direction is 1/683 W/sr.
- The STERADIAN (sr) is the solid angle which, with its vertex in the cen-
tre of a sphere, subtends a spherical cap with an area equal to the squa-
re of the radius.
- LUMINANCE or EMITTANCE is the relationship between the light inten-
sity emitted in a certain direction and the surface that emits it projected
onto a plain perpendicular to the same direction; the measuring unit is the
cd/m
2
(candle/square metre) or its submultiple cd/cm
2
(1 cd/cm
2
=
10,000 cd/m
2
).
Light flux = lumen (lm) = cd/sr
Illuminance = lux (lx) = lm/m
2
Luminance = nit (nit) = cd/m
2
6°