NBN ISO 9847:2020

1.1 This International Standard specifies two preferred methods for the calibration of field pyranometers using reference pyranometers.
1.2 One method, the outdoor calibration or type I,
employs solar radiation as the Source, while the
other method, the indoor calibration or type II, employs an artificial radiation Source.
1.2.1 The outdoor calibration of field pyranometers
may be performed with the pyranometer in a horizontal position (i.e. Zero tilt) (type Ia), in a tilted
Position (type Ib), or at normal incidence (type Ic)
maintaining the receiver surface perpendicular to
the sun’s beam component.
1.2.2 The indoor calibration of field pyranometers
may be performed using an integrating sphere with
shaded (type Ha) or unshaded (type Hb) lamp(s), or
at normal incidence (type HC) frequently using an
Optical bench to present the receiver surface perpendicular to the beam of the lamp.
Types lla and llb correspond to an outdoor calibration under conditions of overcast and sunny sky
with large light cloud fields, respectively. Type Ilc is
comparable with the normal incidence calibration
of type lc.
1.3 The methods of calibration specified are
traceable to the worid radiometric reference (WRR);
traceability to the international Pyrheliometric Scale
of 1956 is not permitted.
1.4 This International Standard is applicable to
most types of field pyranometers regardless of the
type of radiation receptor employed. In general, all
pyranometers used for lang-term monitoring of incident solar irradiance may be calibrated by using the described methods, provided that the reference
pyranorneter has been calibrated at essentially the
Same tilt from horizontal as the tilt employed in the
calibration.
NOTE 1 Pyranometers used for collector tests should
be calibrated using a reference pyrheliometer (see
ISO 9846)