Campbell Scientific HMP60 HMP60 Temperature and Relative Humidity Probe - Page 21

HMP60 Temperature and Relative Humidity Probe VaporPressure() instruction to calculate vapor pressure from temperature and relative humidity measurements (see Section 7.6.1). Edlog dataloggers must first calculate the saturation vapor pressure and then calculate vapor pressure (see Section 7.6.2). TABLE 7-5. Wiring for Vapor Pressure Examples Description Temperature Relative Humidity Signal & Power Reference Power Shield Color Black White Blue Brown Clear CR10(X) SE 3 (2H) SE 4 (2L) G 12 V G CR1000 SE 1 (1H) SE 2 (2H) G 12 V 7.6.1 CR1000 Vapor Pressure Example The VaporPressure() instruction has the following syntax: VaporPressure(Dest,Temp,RH) Where: Dest-the variable in which the results of the instruction will be stored. Temp-the program variable that contains the value for the temperature sensor. The temperature measurement must be in degrees Celsius. RH-the program variable that contains the value for the relative humidity sensor. The relative humidity measurement must be in percent of RH. 'CR1000 Public AirTC Public RH Public VP DataTable(Table1,True,-1) DataInterval(0,60,Min,0) Average(1,AirTC,FP2,0) Sample(1,RH,FP2) Average(1,VP, FP2,0) EndTable BeginProg Scan(5,Sec,1,0) 'HMP60 Temperature & Relative Humidity Sensor measurements AirTC and RH: VoltSE(AirTC,1,mV2500,1,0,0,_60Hz,0.1,-40.0) VoltSE(RH,1,mV2500,2,0,0,_60Hz,0.1,0) If (RH>100) And (RH