IAPWS11_PSUB

This function computes sublimation pressure for ice from temperature with the IAPWS-11 sublimation-curve equation. It is applicable to low-temperature phase-equilibrium checks.

The sublimation relation is:

P_{sub} = f(T)

where T is temperature and P_{sub} is sublimation pressure.

Excel Usage

=IAPWS11_PSUB(T)

• T (float, required): Temperature for sublimation-pressure evaluation (K).

Returns (float): Sublimation pressure of water at the specified temperature (Pa).

Example 1: Sublimation pressure in cryogenic range

Inputs:

T
180

Excel formula:

=IAPWS11_PSUB(180)

Expected output:

0.00539278

Example 2: Sublimation pressure near low-temperature reference

Inputs:

T
230

Excel formula:

=IAPWS11_PSUB(230)

Expected output:

8.94735

Example 3: Sublimation pressure near triple temperature

Inputs:

T
273

Excel formula:

=IAPWS11_PSUB(273)

Expected output:

603.646

Example 4: Sublimation pressure at mid-low temperature

Inputs:

T
250

Excel formula:

=IAPWS11_PSUB(250)

Expected output:

76.0127

Python Code

Show Code

from chemicals.iapws import iapws11_Psub as chemicals_iapws11_psub

def iapws11_psub(T):
    """
    Compute water-ice sublimation pressure from temperature using IAPWS-11.

    See: https://chemicals.readthedocs.io/chemicals.iapws.html#chemicals.iapws.iapws11_Psub

    This example function is provided as-is without any representation of accuracy.

    Args:
        T (float): Temperature for sublimation-pressure evaluation (K).

    Returns:
        float: Sublimation pressure of water at the specified temperature (Pa).
    """
    try:
        return chemicals_iapws11_psub(T)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

T *

Temperature for sublimation-pressure evaluation (K).