- 3 -
1.2.2. Measurement module
The measurement module of the P-200 control unit and the RF200C software constitute
a distinct part of the software and contain the procedures that calculate the
measurement result on the basis of the data downloaded from the meter. These include,
among others, the averaging and rounding-off of the result.
1.3. Technical data
Spectral sensitivity:
V(
λ
) CIE
Measurement field angle:
1º
Measurement field:
Ø 10mm
Spectral matching:
f
1
'
2)
≤
3%
Directional response index:
f
2g
2)
≤
3%
Effect of the surrounding field:
f
2u
2)
≤
1,5%
Linearity:
f
3
2)
≤
0,5%
Temperature coefficient:
K
T
≤
0,02%/K
Measurement ranges
3)
:
500 cd/m
2
50 000 cd/m
2
Measurement resolution:
0.01 cd/m
2
(range 500 cd/m
2
)
1 cd/m
2
(range 50 000 cd/m
2
)
Total error
4)
:
+10°C – +40°C
2.5%
-10°C – +50°C
3.0%
Power supply:
with control unit (5V, 25mA)
Environmental conditions
- temperature:
- relative humidity:
-10°C
÷
+50°C
≤
90% (without condensation)
Dimensions
- measurement probe:
- interface:
Ø25 x 160mm
Ø15 x 42mm
Measurement probe weight:
150g
RF-200C interface weight:
15g
1.3.1. Spectral characteristics
Very good spectral matching of the detector to the spectral sensitivity V(
λ
) is realised
with the use of the set of glass absorption filters. Such a solution guarantees high long-
term and temperature stability, especially in comparison with the cheaper realisations in
which interference filters are used. The quality of this kind of matching ensures the
accurate measurement, regardless of the spectral distributions of the measured
luminous flux, which in the used systems of matrix backlights vary to a great extent from
the spectral efficiency of the calibration illuminant and are the main source of errors.
2)
ISO/CIE 19476 Characterization of the performance of illuminance meters and luminance meters (this standard
replaces CIE publication 69/1987).
DIN 5032-7 Photometry; Classification of illuminance meters and luminance meters
3)
The specified measuring ranges are the minimum values guaranteed by the manufacturer. The actual
values depend on the sensitivity of the detector and the calibration factor and can be even twice as
high
.
4)
The percentage deviation of the measured value for white light sources with any spectral distribution in
the given operating temperature range. It takes into account all the factors affecting the accuracy of
the measurement (spectral and directional mismatch, temperature influence and others). It does not
include the uncertainty of calibration.
