23
Definition
Instrument sensitivity within a specific spectral range
Sensitivity
µV/W/m
²
5 to 15
Definition
Calibration factor
Impedance
Ω
20 to 200, typically 50
Definition
Typical resistance measured at the output
Response time
s
< 18 (95% response)
Definition
Sensor response time
Non-linearity
%
< 1 (from -250 to +250 W/m
2
irradiance)
Definition
Maximum deviation from the responsivity at -100 W/m
2
due to
any change of irradiance within the indicated range.
Temperature dependence of
sensitivity
%
N/S (- 40
°
C to -10
°
C)
< 4 (- 10
°
C to +40
°
C)
N/S (+40 ºC to +80 ºC)
Definition
Maximum error due to any change of ambient temperature with
the indicated interval.
Tilt error
%
< 1 deviation when tilted at any angle off horizontal.
Definition
Maximum deviation from the responsivity at angular tilt with
1000 W/m
²
beam.
Window heating offset
W/m
²
< 6 (0 to 1000 W/m
²
/ solar irradiance)
Definition
Caused by heating of the dome due to solar radiation
Field of view:
Upper detector
Lower detector
180º
150º
Definition
Sensor opening angle
Net irradiance range:
W/m
2
-250 to +250
Definition
Measurement range
Non-stability
%
< 1
Definition
Maximum change per year, percentage of full scale
Spectral selectivity
%
< 5 (8 – 14 µm spectral range)
Definition
Deviation of the product of spectral absorption and spectral
transmittance from the corresponding mean within the indicated
spectral range
Environmental
humidity 0 - 100% RH
Definition
Intended for continuous outdoor use
Uncertainty in daily total
%
< 10
(95 % confidence level) Indoor calibration
Definition
Achievable uncertainty
Temperature sensor
Thermistor and Pt-100
International standards
WMO
ISO
Standards are not available
Instrument calibration
Indoors, side by side against reference CG(R) 3 pyrgeometer
On request outdoors, side by side against reference CG(R) 4
pyrgeometer
