Campbell Scientific ET107 Evapotranspiration Monitoring Station - Manual (Page 109)

Appendix D. Default Programs
For n = 24 To 2 Step -1
Rain(n) = Rain(n-1)
Rain24Ttl = Rain24Ttl + Rain(n)
Next n
RainHrTtl = 0
EndIf
PortSet(9, 1)
Delay(0,200,MSEC)
VoltSe(AirTempC, 1, mV2500, 2, False, 0, _60Hz, 0.1, -40)
VoltSe(RelHum, 1, mV2500, 1, False, 0, _60Hz, 0.1, 0)
If (RelHum >= 100) AND (RelHum < 108) Then RelHum = 100
AirTempF = AirTempC * 1.8 + 32
VoltDiff(SlrRad_W, 1, mV7_5, 3, true, 0, _60Hz, 200, 0)
If (SlrRad_W < 0) Then SlrRad_W = 0
DewPoint (DewPntC,AirTempC,RelHum)
If DewPntC > AirTempC OR DewPntC = NAN Then DewPntC = AirTempC
'Wind chill calculation
'Trap and set any wind speeds higher than 110 to 110.
WC_WSmph = WindSpd_mph
If WC_WSmph > 110 Then WC_WSmph = 110
'Trap and set any airtempF less than -50
WC_AirtempF = AirTempF
If WC_AirtempF < -50 Then WC_AirtempF = -50
WindChilC = 35.74+0.6215*WC_AirtempF-35.75*WindSpd_mph^0.16+0.4275*WC_
AirtempF*WindSpd_mph^0.16
If WindChilC > WC_AirtempF OR WindChilC = NAN Then WindChilC = WC_AirtempF
If WC_AirtempF > 50 OR WindSpd_mph < 3 Then WindChilC = AirTempF
WindChilC = (5/9)*(WindChilC - 32)
'Heat Index calculation
If (AirTempF >= 80) AND (RelHum >= 40) Then
HeatIndxC = -42.379+2.04901523*AirTempF+10.14333127*RelHum-0.22475541*
AirTempF*RelHum-6.83783E-3*AirTempF^2-5.481717E-2*RelHum^2+
1.22874E-3*AirTempF^2*RelHum+8.5282E-4*AirTempF*RelHum^2-1.99E-6*
AirTempF^2*RelHum^2
Else
HeatIndxC = AirTempF
EndIf
If (HeatIndxC < AirTempF) OR (HeatIndxC = NAN) Then HeatIndxC = AirTempF
HeatIndxC = (5/9) * (HeatIndxC - 32)
CallTable VW_Hourly
NextScan
EndProg
D-5