User Manual

LI200X Pyranometer
TABLE 4-1. Multipliers Required for
Average Flux and Total Flux Density in Sl
and English Units
UNITS MULTIPLIER PROCESS
W m
-2
200 Average
MJ m
-2
t * 0.0002 Total
kJ m
-2
t * 0.2 Total
cal cm
-2
min
-1
0.2 * (1.434) Average
cal cm
-2
t * 0.2 * (0.0239) Total
t = datalogger execution interval in seconds
4.1 Example Programs
The following programs measure the LI200X every 10 seconds, and convert
the mV output to Wm
-2
and MJm
-2
. Both programs output an hourly average
flux (Wm
-2
) and a daily total flux density (MJm
-2
). Negative values are set to
zero before being processed. Wiring for the examples is given in Table 4-2.
TABLE 4-2. Wiring for Example Programs
Color Description CR1000 CR10X
Red Signal 1H 1H
Black Signal Reference 1L 1L
White Signal Ground
AG
Clear Shield
G
4.1.1 CR1000 Example Program
In the CR1000 example, a daily total flux density is found. This total flux
density is in MJ m
-2
day
-1
. Negative values are set to zero before they are
added to the running total.
'CR1000
'Declare Variables and Units
Public SlrW
Public SlrMJ
Units SlrW=W/m²
Units SlrMJ=MJ/m²
6