HT instruments HT307 - Manual (Page 8)

HT307
EN - 7
6. TECHNICAL SPECIFICATIONS
6.1. CHARACTERISTICS
Accuracy is referred to the following reference conditions: 23°C ± 5°C with RH < 70%.
The luxmeter is calibrated with a standard incandescent lamp at color temperature
2856°K.
Measuring range and accuracy
Range in lux
20 200 2000 20k 200k
Resolution
0.01 0.1 1 10 100
Accuracy
± (3% rdg)
Range in fc 20 200 2000 20k
Resolution 0.01 0.1 1 10
Accuracy ± (3% rdg)
NOTE: 1fc=10.76Lux, 1Klux=1000Lux, 1Kfc=1000fc
for temperature/color different from the reference, accuracy is 6% rdg
Accuracy on angular deviation from cosine characteristic
30° ± 2%
60° ± 6%
80° ± 25%
6.1.1. Spectral
sensitivity
The photodiode with filters makes the spectral sensitivity meet the CIE photo-optic curve
V(
λ) as shown below.
0
10
20
30
40
50
60
70
80
90
100
380 440 500 560 620 680 740
V(λ)
HT307
Fig. 2: CIE photo-optic curve V( λ).
6.1.2. Photo
detector
The photo detector is a silicon photodiode with spectral response filter.
Relative sensitivit
y
(
%
)
Wavelength (nm)