IAPWS95_RHO

This function computes water density from temperature and pressure using the high-accuracy IAPWS-95 equation of state. It supports liquid, vapor, and supercritical regions within the model validity.

The state relation is:

\rho = f(T, P)

where \rho is mass density, T is temperature, and P is pressure.

Excel Usage

=IAPWS95_RHO(T, P)

T (float, required): Water temperature (K).
P (float, required): Water pressure (Pa).

Returns (float): Water density at the specified state (kg/m^3).

Example 1: Compressed liquid density reference point

Inputs:

T	P
300	1000000

Excel formula:

=IAPWS95_RHO(300, 1000000)

Expected output:

996.96

Example 2: Low pressure high temperature state

Inputs:

T	P
500	100000

Excel formula:

=IAPWS95_RHO(500, 100000)

Expected output:

0.43514

Example 3: Near critical state density

Inputs:

T	P
640	22000000

Excel formula:

=IAPWS95_RHO(640, 22000000)

Expected output:

524.064

Example 4: Very high temperature and pressure state

Inputs:

T	P
1200	50000000

Excel formula:

=IAPWS95_RHO(1200, 50000000)

Expected output:

94.2499

Python Code

Show Code

from chemicals.iapws import iapws95_rho as chemicals_iapws95_rho

def iapws95_rho(T, P):
    """
    Compute water density from temperature and pressure using IAPWS-95.

    See: https://chemicals.readthedocs.io/chemicals.iapws.html#chemicals.iapws.iapws95_rho

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

    Args:
        T (float): Water temperature (K).
        P (float): Water pressure (Pa).

    Returns:
        float: Water density at the specified state (kg/m^3).
    """
    try:
        return chemicals_iapws95_rho(T, P)
    except Exception as e:
        return f"Error: {str(e)}"

Online Calculator

T *

Water temperature (K).

P *

Water pressure (Pa).