Measuring illuminance
Measuring instruments:
Description and precision
– maximum precision, tolerance 3%
– high precision, tolerance 5%
–
B: average precision; tolerance 10%
(minimum requirement)
Measuring conditions
–
Avoid external light/daylight
(measure separately and subtract)
–
Check mains voltage and ambient
temperature
–
Use new, burnt-in lamps (discharge
lamps 100 h)
Measuring grid and measuring level
In order facilitate inspection the light‑
ing system, the measuring grid has been
specified the 12464 (Lighting work-
places) and 12193 (Lighting sports
facilities) standards.
The following recommendations apply for the
height the measuring levels:
–
Workplaces 0.2 m
5 0.19
The Lighting Handbook
The Mean illuminance the arithmetic
brilliance level measured with luxmeter
in defined grid, under precisely specified
conditions.6 m
10 m
50 m
100.03 m
–
Circulation areas, stairs,
car parks (floor) 0.2 m
– Measuring grid: congruent triangles
–
Measuring grid not congruent with
luminaire layout grid
Size measuring field Grid element spacing
1 0.75 m;
sports facilities (floor) 0.03 m
– Cylindrical illuminance 1
