FB_BA_HX

This function block FB_BA_HX is used to calculate the dew point temperature, the specific enthalpy and the absolute humidity. The temperature, the relative humidity and the barometric air pressure are required for the calculation of these parameters.
Enthalpy is a measure of the energy of a thermodynamic system.

Inputs

VAR_INPUT
  fT       : REAL;
  fHumRel  : REAL;
  fAP      : REAL;
END_VAR

Name	Type	Description
fT	REAL	Temperature [°C].
fHumRel	REAL	Relative humidity [%]
fAP	REAL	Hydrostatic air pressure at 1013.25 hPa.

Outputs

VAR_OUTPUT
  fHumAbs  : REAL;
  fDewPnt  : REAL;
  fE       : REAL;
  fDHA     : REAL;
  fSpecV   : REAL;
  fTWet    : REAL;
END_VAR

Name	Type	Description
fHumAbs	REAL	Absolute humidity g water per kg dry air [g/Kg].
fDewPnt	REAL	Dew point temperature [°C]
fE	REAL	Enthalpy [kJ/kg]
fDHA	REAL	Density of moist air ρ [kg mixture/m³]
fSpecV	REAL	Specific volume [m³/kg]
fTWet	REAL	Wet bulb temperature [°C]

Requirements

Development environment	Required PLC library
TwinCAT from v3.1.4024.22	Tc3_BA2 from v5.2.5.0