Campbell Scientific LP02 Hukseflux Pyranometer - Manual (Page 21)

LP02 Pyranometer
9: Average (P71)
1: 1 Reps
2: 3 Loc [ Solar_Wm2 ]
10: If time is (P92)
1: 0 Minutes (Seconds --) into a
2: 1440 Interval (same units as above)
3: 10 Set Output Flag High (Flag 0)
11: Set Active Storage Area (P80)
1: 1 Final Storage Area 1
2: 102 Array ID
12: Real Time (P77)
1: 1220 Year,Day,Hour/Minute (midnight = 2400)
13: Resolution (P78)
1: 1 High Resolution
14: Totalize (P72)
1: 1 Reps
2: 4 Loc [ Solar_MJ ]
15: Resolution (P78)
1: 0 Low Resolution
7.2.5 Output Format Considerations
In CRBasic, store the data in the IEEE4 format if the measurements will be
totalized.
When using Edlog, the largest number the datalogger can store in Final Storage
is 6999 in low resolution mode (FP2) and 99999 in high resolution mode (if
available). If the measurement value is totalized, there is some danger of over-
ranging the output limits, as shown in the following example:
Example
Assume that daily total flux is desired, and that the datalogger scan rate is 1
second. With a multiplier that converts the readings to units of kJm –2 and an
average irradiance of 0.5k W m –2 , the maximum low resolution output limit
will be exceeded in less than four hours.
The following solutions can be used to prevent overranging:
Solution 1 – Change the multiplier in the instruction to (m•0.0001). This will
totalize MJ m –2 instead of kJm –2 .
Solution 2 – Record the average flux density and later multiply the result by the
number of seconds in the output interval to arrive at total flux.
Solution 3 – Record the total flux using the high resolution format. The
drawback to high resolution is that it requires four bytes of memory per data
point, consuming twice as much memory as low resolution. Instruction 78 is
used to switch to high resolution in the Edlog dataloggers.
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