Campbell Scientific HFP01SC Hukseflux Self-Calibrating Soil Heat Flux Plate User Manual

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Model HFP01SC Self-Calibrating Soil Heat Flux Plate

BeginProg
'HFP01SC factory calibration in W/(m^2 mV) = 1000/sensitivity.
shf_cal(1) = HFP01SC_CAL_1
shf_cal(2) = HFP01SC_CAL_2
shf_cal(3) = HFP01SC_CAL_3
shf_cal(4) = HFP01SC_CAL_4

Scan (1,Sec,3,0)
'Measure the HFP01SC soil heat flux plates.
VoltDiff (shf_mV(1),4,mV50C,9,TRUE,0,_60Hz,1,0)

'Apply calibration to HFP01SC soil heat flux plates.
For ii = 1 To 4
shf(ii) = shf_mV(ii)*shf_cal(ii)
Next ii

'Power the HFP01SC heaters.
PortSet (9,sw12_1_state)

'Measure voltage across the heater (Rf_V).
VoltSe (V_Rf(1),4,mV5000,25,TRUE,0,_60Hz,0.001,0)

CallTable (mean)

'Begin HFP01SC calibration on a fixed interval.
If ( IfTime (1,CAL_INTERVAL,Min) ) Then
shf_cal_on_f = TRUE
Move (shf_mV_0(1),4,shf_mV(1),4)
sw12_1_state = TRUE
EndIf

If ( IfTime (4,CAL_INTERVAL,Min) ) Then
Move (shf_mV_180(1),4,shf_mV(1),4)
Move (V_Rf_180(1),4,V_Rf(1),4)
sw12_1_state = FALSE
EndIf

If ( IfTime (END_CAL,CAL_INTERVAL,Min) ) Then
Move (shf_mV_end(1),4,shf_mV(1),4)
'Compute new HFP01SC calibration factors.
For ii = 1 To 4
shf_cal(ii) = V_Rf_180(ii)*V_Rf_180(ii)*128.7/ABS (((shf_mV_0(ii)+shf_mV_end(ii))/2)-shf_mV_180(ii))
Next ii
shf_cal_on_f = FALSE
EndIf
NextScan
EndProg