HT instruments HT309 - Manual (Page 10)

HT309
EN - 9
6. TECHNICAL SPECIFICATIONS
6.1. TECHNICAL CHARACTERISTICS
Accuracy is referred to the following reference conditions: temperature 23°C ± 5°C with
relative humidity < 70%RH.
The instrument is calibrated for a standard white light source consisting of an incandescent
lamp, at a temperature/colour of 2856°K in compliance with Class A.
Calibration for LED sources (with spectrum response different from that of standard white
light) is based on the calibration for standard white light source in Class A using the
appropriate correction factors (see Table 1)
Illuminance measurement (Autorange)
Full scale (Lux) 40 400 4000 40k 400k
Resolution (Lux) 0.01 0.1 1 10 100
Accuracy ± (3%reading)
Full scale (Fc) 40 400 4000 40k
Resolution (Fc) 0.01 0.1 1 10
Accuracy ± (3%reading)
NOTE 1: 1Fc=10.76Lux, 1Klux=1000Lux, 1Kfc=1000Fc
NOTE 2: for temperature/colours different from the reference one, accuracy becomes 6%reading
Distance range for luminous intensity measurement: 0.01 ÷ 30.47m / 0.01 ÷ 99.99ft
Accuracy on angular deviation from cosine characteristic
30° ± 2%
60° ± 6%
80° ± 25%
6.1.1. Spectrum
response
The spectrum response of the photodiode with filter is almost identical to the CIE photo-
optical curve V(
λ) as shown in the following graph.
0
10
20
30
40
50
60
70
80
90
100
380 440 500 560 620 680 740
V(?)
HT307
Fig. 2: CIE curve V( λ).
6.1.2. Sensor
The sensor is a silicon photodiode with filter on the spectrum response.
Relative sensitivit
y
(%
)
Wavelength (nm)
HT309
V(λ)