Kipp&Zonen BSRN Scientific Solar Monitoring System - Manual (Page 105)

93
(bubble half out of the ring)
Coincident with base of the instrum ent.
Detector surface and base are coplanar within 0.1°
Materials Anodized alum inium case. Stainless steel screws in stainless
steel bushes. W hite plastic screen of ASA
Drying cartridge PMMA
W eight 830 g
Cable length 10 m (standard)
Dim ensions 91.5 m m total height, 150 m m diam eter, 25 m m dom e height,
50 m m dom e diam eter
B 2.3 Kipp & Zonen Delft BV CM21/31 Pyranom eters
Suitable for the m easurem ent of solar irradiance on a plane surface.
- im proved specifications in com parison with the CM11.
- also available with quartz dom es (CM31) yielding a broader range and reduced offsets.
Essentially the pyranom eter CM21 has the sam e characteristics as the CM11. Som e of these specifications
have been im proved:
Sensitivity
Im pedance
Tem perature response
Non-linearity
Response tim e
Specifications
Response tim e < 5 s
tim e for 95 % response
Zero off-set
a) response to 200 W m net
+ 7 W m -2 -2
therm al radiation (ventilated)
b) response to 5 K h change
± 2 W m -1 -2
in am bient tem perature
Non-stability ± 0.5 %
percentage change in
responsivity per year
Non-linearity ± 0.25 %
percentage deviation from the
responsivity at 500 W m due
-2
to the change in irradiance
within 100 W m to 1000 W m
-2 -2
Directional response for beam ± 10 W m -2
radiation
The range of errors caused by
assum ing that the norm al incidence
responsivity is valid for all directions
when m easuring from any direction a
beam radiation whose norm al incidence
irradiation is 1000 W m
-2