Campbell Scientific CS300 Silicon Pyranometer - Manual (Page 20)

CS300 Pyranometer
8. Maintenance and Calibration
On a monthly basis the level of the pyranometer should be checked. Any dust
or debris on the sensor head should be removed. The debris can be removed
with a blast of compressed air or with a soft bristle, camel hair brush.
Handle the sensor carefully when cleaning. Be careful not
to scratch the surface of the sensor.
Recalibrate the CS300 every three years. Obtain an RMA number before
returning the CS300 to Campbell Scientific, Inc. for recalibration.
9. Troubleshooting
Symptom: –9999 or radiation values around 0
1. Check that the sensor is wired to the single-ended channel specified by the
measurement instruction.
2. Verify that the range code is correct for the datalogger type.
3. Disconnect the sensor leads from the datalogger and use a DVM to check
the voltage between the red (+) and the black (–) wires. The voltage
should be 0 to 200 mV for 0 to 1000 Wm –2 radiation. No voltage
indicates a problem with either the photodiode or the shunt resistor, both
of which are potted in the sensor head and cannot be serviced.
Symptom: Incorrect solar radiation
1. Make sure the top surface of the sensor head is clean, and that the sensor
is properly leveled.
2. Verify that the range code, multiplier and offset parameters are correct for
the desired engineering units and datalogger type.
Jumps of 3 to 6 Wm –2 are typical of CR200(X) measurements, due
to the 0.6 mV CR200(X) resolution and the 0.2 mV/Wm –2 CS300
sensitivity.
CAUTION
NOTE
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