HD 9021/Cd
Probe for measuring LUMINANCE, measuring range from 0 to 1999x103 candles/cm2. Measuring angle 6° with opening surface 25 mm. CIE filter for correction according to the human eye.
6°
-The CANDLE (cd) is the light intensity in a specific direction of a source that emits monochrome radiation at a frequency of 540x1012 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/m2 (candle/square metre) or its submultiple cd/cm2 (1 cd/cm2 = 10,000 cd/m2).
Light flux | = | lumen (lm) | = | cd/sr |
Illuminance | = | lux (lx) | = | lm/m2 |
Luminance | = | nit (nit) | = | cd/m2 |
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