Cfr manual 25 – Kipp&Zonen CFR Calibration Facility User Manual
Page 26
CFR manual
25
Appendix II: Pyranometer Classification According to WMO Guide 1996
Characteristics
CMP 22
CMP 21
CMP 11
CMP 6
High
quality
Good
quality
Moderate
quality
ISO 9060 classification
Secondary
Standard
Secondary
Standard
Secondary
Standard
First
Class
Secondary
Standard
First
Class
Second
Class
Response time (95 percent
response)
5 s
5 s
5 s
18 s
< 15 s
< 30 s
< 60 s
Zero offset:
(a) Response to 200 W/m
2
net thermal radiation
(ventilated)
(b) Response 5 K/h change
in ambient temperature
± 3 W/m
2
± 1 W/m
2
± 7 W/m
2
± 2 W/m
2
± 7 W/m
2
± 2 W/m
2
± 15 W/m
2
± 4 W/m
2
± 7 W/m
2
± 2 W/m
2
± 15 W/m
2
± 4 W/m
2
± 30 W/m
2
± 8 W/m
2
Resolution (smallest detectable
change)
± 1 W/m
2
± 1 W/m
2
± 1 W/m
2
± 1 W/m
2
± 1 W/m
2
± 5 W/m
2
± 10 W/m
2
Stability (change per year,
percentage of full scale)
< 0.5
< 0.5
< 0.5
< 1
± 0.8
± 1.5
± 3.0
Directional response of beam
radiation
(The range of errors caused by
assuming that the normal incidence
responsivity is valid for all
directions when measuring, from
any direction, a beam radiation
whose normal incidence irradiance
is 1000 W/m
2
)
± 5 W/m
2
± 10 W/m
2
± 10 W/m
2
± 20 W/m
2
± 10 W/m
2
± 20 W/m
2
± 30 W/m
2
Temperature response (percentage
of maximum due to any change of
ambient temperature within an
interval of 50 K)
± 0.5
-20
0
C-+50
0
C
± 1
-20
0
C-+50
0
C
± 1
-10
0
C-+40
0
C
± 4
-10
0
C-+40
0
C
± 2
± 4
± 8
Non-linearity (percentage deviation
from the responsivity at 500 W/m
2
due to any change of irradiance
within the range 100 to 1000 W/m
2
)
± 0.2
± 0.2
± 0.2
± 1
± 0.5
± 1
± 3
Spectral sensitivity (percentage of
deviation of the product of spectral
absorptance and spectral
transmittance from the
corresponding mean within the
range of 0.3 to 3 µm)
± 2
± 5
± 10
Tilt response (percentage deviation
from the responsivity at 0° tilt,
horizontal, due to change in tilt
from 0° to 90° at 1000 W/m
2
irradiance)
± 0.2
± 0.2
± 0.2
± 1
± 0.5
± 2
± 5
Achievable uncertainty, 95 percent
confidence level
Hourly totals
Daily totals
1 %
2 %
2 %
5 %
3%
2%
8%
5%
20%
10%