Campbell Scientific CNR4 Net Radiometer - Manual (Page 40)

CNR4 Net Radiometer
9. Maintenance
n.
9.1 Cleaning W
9.2 Recalibrat
e
uthorized Kipp & Zonen
calibration facility.
librated every two years. Alternatively, one can
of pyrgeometers,
9.3 Replacing
screws
compartment
sealed. The CNR4 comes with two spare drying cartridges. Additional drying
an be purchased from Campbell Scientific.
and Recalibration
The CNR4 is weatherproof, and is intended for a continuous outdoor use. The
materials used in the pyranometer and the pyrgeometer are robust and require
little maintenance. For optimal results, however, proper care must be take
indows and Domes
The radiometer readings can be reduced if domes and windows are not clean.
The site operator should check the windows and domes of the CNR4 regularly,
and clean them as needed. Use distilled water or alcohol as cleaning solution,
being careful not to scratch the windows and domes during cleaning.
ion
For quality assurance of the measured data, the manufacturer recommends th
CNR4 be recalibrated on a regular schedule by an a
The CNR4 should be reca
check the sensor calibration by letting a higher standard run parallel to it over a
two-day period and, then, comparing the results. For comparison of
pyranometers, one should use a clear day. For comparison
one should compare the nighttime results. If the deviations are greater than
6%, the sensor should be recalibrated.
Please contact Campbell Scientific to obtain an RMA number for recalibration.
the Drying Cartridge
The CNR4 has a drying cartridge inside the sensor to help keep the electronics
dry. The manufacturer recommends replacing the drying cartridge every 6 to
12 months. The three screws holding the white solar shield and the six
holding the aluminium base plate need to be removed to access the drying
cartridge, as shown in FIGURE 9-1. Make sure that the black rubber gasket is
put in place properly before the base plate is put back to keep the
cartridges, pn 26006, c
32