StmSI_SPH
- Last UpdatedSep 17, 2025
- 1 minute read
- PI System
- PI Server 2023
- PI Server
Calculates the vapor specific entropy as a function of pressure and enthalpy—all variables expressed in SI units. Use for both superheated and wet steam.
Format
StmSI_SPH(P, H)
Arguments
-
P
Pressure of the steam in KPa. The valid range is 0.611213 to 100000 KPa.
-
H
Computed vapor specific enthalpy in J/g. The valid range is -2.326 to 4326.36 J/g.
Returns
Computed vapor specific entropy in J/g/K or Error digital state.
Sample Values
|
Pressure |
Enthalpy |
Entropy |
State |
|
2500. |
3685.1 |
7.5956 |
Superheated |
|
5000. |
3664.5 |
7.2578 |
Superheated |
|
10000. |
3622.7 |
6.9009 |
Superheated |
|
40000. |
3346.4 |
6.0124 |
Superheated |
|
2500. |
2617.0 |
5.8837 |
90 % vapor |
Note: Even if the input enthalpy is less than that of the saturated liquid, the function still computes the entropy by extrapolation without setting an error state.