Campbell CS300 Instruction Manual - page 10
CS300 Pyranometer
Solar radiation can be recorded as an average flux density (W m
-2
) or daily
total flux density (MJ m
-2
). The appropriate multipliers are listed in Table 5-1.
Negative values should be set to zero before being processed.
TABLE 5-1. Multipliers Required for Average Flux
and Total Flux Density in SI and English Units
UNITS MULTIPLIER
PROCESS
W m
-2
5.0 Average
MJ m
-2
t * 0.000005
Total
kJ m
-2
t * 0.005
Total
cal cm
-2
min
-1
0.005 * (1.434)
Average
cal cm
-2
t * 0.005 * (0.0239)
Total
t = datalogger execution interval in seconds
Nearby AC power lines, electric pumps, or motors can be a source of electrical
noise. If the sensor or datalogger is located in an electrically noisy
environment, the measurement should be made with the 60 or 50 Hz rejection
integration option as shown in the example programs.
5.1 Example Programs
The following programs measure the CS300 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 5-2.
TABLE 5-2. Wiring for Example Programs
Color Description
CR1000 CR10X
Red
Signal
SE 1
SE 1
Black Signal
Ground
AG
Clear Shield
G
5.1.1 CR1000 Example Program
'CR1000
'Declare Variables and Units
Public SlrW
Public SlrMJ
Units SlrW=W/m²
Units SlrMJ=MJ/m²
5