User Manual

SP-LIT E Si licon Pyran ometer
8
5.1 Datalogger I nput Range Codes
Normally the 15 mV range for the 21X and CR7, the 25 mV range for the
CR10(X), CR500/CR510, and CR1000, and the 50 mV range for the CR23X
are suitable.
The parameter code for the input range also specifies the measurement
integration time. T he slow or 60 Hz rejection integration gi ves a more noise-
free reading. A fast integration takes less power and allows for faster
throughput. Measurement instructions for the CR1000 have a separate
parameter for the integration time.
5.2 Calibration Factor and Multiplier
All SP-LITE sensors have a sensitivity, or calib ratio n factor, of 10 µV/(W m
-2
).
Solar radiation can be reported as an average flux density (W m
-2
) or daily total
flux dens ity (MJ m
-2
). The appropriate multipliers for the measurement
instruction are listed in Table 3. Programming examples are given for both
average and daily total solar radiation.
TABLE 3. M ultipliers Required for Flux Density and Total
Fluxes
Units Multipliers Output Processing
MJ m
-2
t*0.0001 (P72 total fluxes)
KJ m
-2
t*0.1 (P72 total fluxes)
W m
-2
100 (P71 flux density)
KW m
-2
0.1 (P71 flux density)
cal cm
-2
t*0.0239*0.1 (P72 total fluxes)
cal cm
-2
min
-1
1.434*0.1 (P71 flux density)
t = the datalogger program execution interval in seconds
5.3 Program Example 1, Average Solar Radiation
The examples below give the appropriate datalogger code for the CR10X
datalogger, using either Instruction 2 (differential) or Instruction 1 (single -
ended).
Example 1 shows the program instructions used to measure the signal from the
SP-LITE. A thirty-minute average is calculated and stored in final storage.
Wiring for Example 1
Color Function
Example CR10X
Program Channels
Used
White Radiation Signal 1H
Green Signal Reference 1L
Jumpered to AG
Clear Shield G