Calibration

Spectral reflectance    
in different
geometrics *)

0.5-100%

2.0%

Calibration standards for spectral measurement instruments

The coefficient
of specific
retroreflection R'

3-106 cd/(lx x m2)

3.2%

Retroreflecting materials

Retroreflection

coefficient RL

130-180 mcd/
(m2 x lx)

+/- 5 mcd/
(m2 x lx)

Road measurement instruments (LTL800, LTL 2000, LPL 2000SQ, LTLX)

Mean luminance

coefficient QD

50-200 mcd/
(m2 x lx)

+/- 4 mcd/
(m2 x lx)

Road measurement instruments

(QD30)

Luminuous flux

5-20.000 lm
50-50.000 lm
250-6.000 lm

1.1%

1.5%

1.2%

Incandescent lamps

Discharge lamps

Fluorescent tubes/lamps

Luminous intensity

1-106 cd

1.6%

Luminous intensity standards

Illuminance

1-700 lx

2.3%

Illuminance standards

Luminance

0.15-1.500 cd/m2

2.8%

Luminance standards

Illuminance

1-2500 lx

2.2%

Illuminance meters

Luminance

3-750 cd/m2

1.8%

Luminance meters