This function block calculates different values from the temperature and relative humidity like the enthalpy, dewpoint or absolute humidity.
Figure 1: Psychrometric - Wire Sheet |
Figure 2: Psychrometric - Property Sheet |
Figure 3: Psychrometric - Logic Diagram
Input
Input Name |
Description |
Temperature |
This is 32-bit floating point input slot. It depends on the global setting for the controller. |
Rel Humidity |
This is 32-bit floating point input slot. It is measured in percentage (%). |
Table 1:Inputs of Psychrometric Function
Output
Output Name |
Description |
Out |
Output = Enthalpy (kJ/kg or BTU/LB), Dewpoint, or Absolute humidity (g/kg, kg/m3, g/m3) (Depends on the selected operation). |
Table 2:Outputs of Psychrometric Function
Parameter
Parameter Name |
Description |
Operation |
There are three operations: Enthalpy, Dewpoint, and AbsHumidity.
|
Out Save |
Master Sync Enabled: If you set it to "true" the last output will be set as output for one cycle after the controller restarts. The application can use it to return to the same state before the controller restart. Out: To enable or disable the Out feature. |
Table 3:Parameters of Psychrometric Function
Example
1. Operation is Enthalpy (Enthalpy = 42.3 kJ/kg)
Figure 4: Psychrometric Example with Enthalpy
2. Operation is Dewpoint (Dewpoint = 7.03°C)
Figure 5: Psychrometric Example with Dewpoint
3. Operation is Absolute Humidity (Absolute Humidity = 6.23 kg/m3)
Figure 6:Psychrometric Example with Absolute Humidity
Refer to General Description for general information about IRMN4 Function Blocks.