Campbell CMP11-L, Instruction Manual

Page: 28 / 42

CMP6-L, CMP11-L, and CMP21-L Pyranometers
'CR1000 Series Datalogger
Public PTemp
Public Batt_Volt
Public CMP21_Irr
Public CMP21_T_C
Public CMP21_T_K
Dim Rs,Vs_Vx
Units CMP21_Irr = W/m2
Units CMP21_T_C = Degrees C
Units CMP21_T_K = Degrees K
DataTable (TenMin,1,-1)
DataInterval (0,1,Min,8)
Minimum (1,Batt_Volt,FP2,0,False)
Sample (1,PTemp,FP2)
Average (1,CMP21_Irr,FP2,False)
StdDev (1,CMP21_Irr,FP2,False)
Average (1,CMP21_T_C,FP2,False)
StdDev (1,CMP21_T_C,FP2,False)
Average (1,CMP21_T_K,FP2,False)
StdDev (1,CMP21_T_K,FP2,False)
EndTable
BeginProg
Scan (1,Sec,0,0)
‘Measure the Battery Voltage and Panel Temperature
PanelTemp (PTemp,250)
Battery (Batt_Volt)
‘Measure the CMP21 pyranometer
VoltDiff (CMP21_Irr,1,mV25C,3,True,10000,_60Hz,1000/8.65,0)
'CMP21 Thermistor Measurement
BrHalf (Vs_Vx,1,mV5000,15,Vx1,1,2500,True ,0,250,1.0,0)
Rs = 1000*(Vs_Vx/(1-Vs_Vx))
CMP21_T_C = 1/(1.0295e-3+2.391e-4*LN(Rs)+1.568e-7*(LN(Rs))^3)-273.15
'Convert CMP21 temp to Kelvin.
CMP21_T_K = CM273.15
CallTable TenMin
NextScan
EndProg
7.3.3.4 CR10X Example Program for Measuring a CMP6
The following program uses a CR10X to measure a CMP6 every 10 seconds
and convert the mV output to W
• m
–2
and MJ • m
–2
. A sensor calibration of
14.33 µV / W • m
–2
is used for this example program. The program outputs an
hourly average flux (W
•
m
–2
), and a daily total flux density (MJ
•
m
–2
).
20