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Maintenance
The station requires minimal maintenance. At least once a year, the station should be
visually inspected. When visually inspecting the station, make sure that the front of the
enclosure is facing the equator. Check to see if the sensor assembly is vertically level.
When inspecting the PV cell temperature sensor, check for any damage to the sensor
head or cabling.
The pyranometer should be thoroughly checked for cleanliness. Debris on the
pyranometer is a common cause of low output readings. Deposits can accumulate on the
sensor from evaporation of sprinkler irrigation water and dust, which can accumulate
during periods of low rainfall. Any salt deposits should be dissolved and removed with
vinegar and a soft cloth or q-tip. Dust and other organic deposits are best removed with
water, rubbing alcohol or window cleaner. Never use an abrasive cleaner on the lens.
Calibration
Research indicates that the pyranometer output increases about 1% per year because of
changes in the optical transparency of the diffusion disk. The station can be returned for
recalibration every12 months. If this is not done the 1% increase in reading should be
compensated for in the data acquisition software.
The temperature sensors generally have negligible drift over time and can not be
calibrated. When they fail they generally fail to a short or open circuit. This causes their
reported readings to go to either extreme.
For optimum performance Rainwise recommends the station be recalibrated every 12
months.
