Water Density Calculator Pressure Temperature

Water Density Equation:

\[ \rho = \rho_0 \times \exp(-\beta (T - T_0) + \kappa (P - P_0)) \]

Reference Density (ρ₀):

kg/m³

Thermal Expansion Coefficient (β):

/°C

Isothermal Compressibility (κ):

/Pa

Temperature (T):

°C

Reference Temperature (T₀):

°C

Pressure (P):

Reference Pressure (P₀):

Calculated Density (ρ):

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1. What is the Water Density Equation?

The water density equation calculates the density of water at different temperatures and pressures. It accounts for thermal expansion and isothermal compressibility effects on water density.

2. How Does the Calculator Work?

The calculator uses the water density equation:

\[ \rho = \rho_0 \times \exp(-\beta (T - T_0) + \kappa (P - P_0)) \]

Where:

\( \rho \) — Calculated density (kg/m³)
\( \rho_0 \) — Reference density (kg/m³)
\( \beta \) — Thermal expansion coefficient (/°C)
\( \kappa \) — Isothermal compressibility (/Pa)
\( T \) — Temperature (°C)
\( T_0 \) — Reference temperature (°C)
\( P \) — Pressure (Pa)
\( P_0 \) — Reference pressure (Pa)

Explanation: The equation accounts for how water density changes with temperature (thermal expansion) and pressure (compressibility).

3. Importance of Water Density Calculation

Details: Accurate water density calculation is crucial for fluid dynamics, oceanography, engineering applications, and scientific experiments where precise density measurements are required.

4. Using the Calculator

Tips: Enter all parameters in the correct units. Default values are provided for standard conditions (20°C, 1 atm). For pure water at 20°C, typical values are ρ₀=998.2 kg/m³, β=0.000214 /°C, κ=4.5×10⁻¹⁰ /Pa.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this equation?
A: This is an approximate equation. For precise calculations, especially at extreme temperatures/pressures, more complex equations of state should be used.

Q2: What's the density of water at standard conditions?
A: At 20°C and 1 atm, pure water density is approximately 998.2 kg/m³.

Q3: How does temperature affect water density?
A: Water density decreases with increasing temperature (above 4°C) due to thermal expansion.

Q4: How does pressure affect water density?
A: Water density increases slightly with pressure due to compressibility, though water is relatively incompressible compared to gases.

Q5: Does this work for seawater?
A: This calculator is for pure water. Seawater requires additional salinity parameters for accurate density calculation.