Campbell Scientific NR-LITE-L Kipp and Zonen Net Radiometer - Manual (Page 13)

NR-LITE Net Radiometer
5. Datalogger Programming
This section is for users who write their own datalogger
programs. A datalogger program to measure this sensor can be
generated using Campbell Scientific’s Short Cut Program
Builder Software. You only need to read the calibration portion
of this section if using Short Cut. NOTE
The NR-LITE outputs a low-level voltage ranging from 0 to a maximum of
about 15 mV. A differential voltage measurement (VoltDiff in CRBasic or
Instruction 2 in Edlog) is recommended because it has better noise rejection
than a single-ended measurement. If a differential channel is not available, a
single-ended measurement (VoltSE in CRBasic or Instruction 1 in Edlog) can
be used. The acceptability of a single-ended measurement can be determined
by simply comparing the results of single-ended and differential measurements
made under the same conditions.
5.1 Input Range and Integration
Normally the 15 mV range for the 21X or CR7, the 25 mV range for the
CR800, CR850, CR1000, CR10(X) or CR500/CR510, and the 50 mV range for
the CR3000, CR5000, or CR23X are suitable.
The slow or 60 Hz rejection integration gives a more noise-free reading. A fast
integration takes less power and allows for faster throughput.
5.2 Calibration Factor
Each NR-LITE is provided with a ‘Certificate of Calibration’ by the
manufacturer which shows the sensor serial number and a ‘sensitivity’ or
calibration factor. This calibration factor, after conversion, is used in the
datalogger program. Always cross check to ensure that the serial number of
your NR-LITE and the number on the calibration certificate are identical. The
serial number and sensitivity are also shown on a small label attached to the
connecting arm near the head of the sensor itself.
The calibration factor provided by Kipp & Zonen is in units of uV/(W m -2 ),
which needs to be converted to units of (W m -2 )/mV for the multiplier
parameter in the datalogger program. To convert the units, divide the
calibration factor into 1000. For example, if the calibration factor is 15.8
uV/(W m
-2 ), the multiplier is:
1000/15.8 = 63.29 (W m -2 )/mV
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