Campbell CS300 Instruction Manual - page 13
CS300 Pyranometer
13: Real Time (P77)
1: 1220
Year,Day,Hour/Minute (midnight = 2400)
14: Resolution (P78)
1: 1
High
Resolution
15: Totalize (P72)
1: 1
Reps
2: 2
Loc [ SlrMJ ]
16: Resolution (P78)
1: 0
Low
Resolution
5.2 Total Solar Radiation
If solar radiation is totalized in units of kJ m
-2
, there is a possibility of
overranging the output limits. For CRBasic dataloggers, you can avoid this by
using the IEEE4 or long data format. With the Edlog dataloggers the largest
number that the datalogger can output to final storage is 6999 in low resolution
(default), and 99999 in high resolution.
For Edlog dataloggers, if you assume that the daily total flux density is desired
in kJ m
-2
and assume an irradiance of 0.5 kW m
-2
, the maximum low resolution
output limit will be exceeded in just under four hours. This value was found
by taking the maximum flux density the datalogger can record in low
resolution and dividing by the total hourly flux density.
3 9
6999
0 5
3600
2
2
1
1
.
.
hr
kJ m
kJ m
s
s hr
(1)
To circumvent this limitation for Edlog dataloggers, record an average flux.
Then, during post processing, multiply the average flux by the number of
seconds in the output interval to arrive at a output interval flux density. Sum
the output interval totals over a day to find a daily total flux density.
Another alternative for Edlog dataloggers is to record total flux using the high
resolution format. Instruction 78 is used to switch to the high resolution. The
disadvantage of the high resolution format is that it takes more memory per
data point.
6. 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.
CAUTION
8