Campbell Scientific CNR4 Net Radiometer - Manual (Page 32)

CNR4 Net Radiometer
Scan (1,Sec,3,0)
PanelTemp (logger_temp,250)
Battery (batt_volt)
'CNR4 radiation measurements
VoltDiff (cnr4(),4,mV20C,1,True ,0,_60Hz,cnr4_mult(),0)
'CNR4 thermistor measurement
BrHalf (Vs_Vx,1,mV2500,16,Vx2,1,2500,True ,0,250,1.0,0)
Rs = 1000*(Vs_Vx/(1-Vs_Vx))
cnr4_T_C = 1/(1.0295e-3+2.391e-4*LN(Rs)+1.568e-7*(LN(Rs))^3)-273.15
'Convert CNR4 temperature to Kelvin
cnr4_T_K = cnr4_T_C+273.15
'Correct the long-wave radiation values from pyrgeometers
long_up_corr = long_up+5.67e-8*cnr4_T_K^4
long_dn_corr = long_dn+5.67e-8*cnr4_T_K^4
'Compute short-wave net radiation
Rs_net = short_up - short_dn
'Compute long-wave net radiation
Rl_net = long_up - long_dn
'Compute albedo
albedo = short_dn/short_up
'Compute net radiation
Rn = Rs_net + Rl_net
CallTable cnr4_data
CallTable cnr4_ts
NextScan
EndProg
7.3. ing Differential Measurements
ur differential channels to measure the four radiation
channel and one single-ended channel to measure
m measures the sensors every 1 second, performs
g of the data and stores the following processed data to a
r4_data once every 60 minutes. It also stores the raw time-
R4 to data table called cnr4_ts.
Minimum battery voltage
ple datalogger panel temperature
rage short-wave radiation (pyranometer up)
rage short-wave radiation (pyranometer down)
rage long-wave radiation (pyrgeometer up)
age long-wave radiation (pyrgeometer down)
Average CNR4 thermistor temperature (degrees C)
Average CNR4 thermistor temperature (Kelvin)
ave radiation (pyrgeometer up)
ave radiation (pyrgeometer down)
diation
diation
Average albedo
Average net radiation
2.2 Example 2, CR3000 Program Us
Example 2 requires fo
outputs and one excitation
the thermistor. The progra
the online processin
data table called cn
series data from CN
Sam
Ave
Ave
Ave
Aver
Average corrected long-w
Average corrected long-w
Average short-wave net ra
Average long-wave net ra
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