1. What is Specific Gravity of Water in lb/in³?

Definition: The density of water at standard conditions is 0.036127 pounds per cubic inch (lb/in³), which serves as the reference for specific gravity calculations.

Purpose: This value is used to convert specific gravity (unitless ratio) to actual density values in lb/in³ for engineering and scientific calculations.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \rho_{material} \) — Density of material (lb/in³)
• \( SG \) — Specific gravity of material (unitless)
• \( \rho_{water} \) — Density of water (0.036127 lb/in³)

Explanation: Specific gravity is multiplied by water's density to obtain the material's density in pounds per cubic inch.

3. Importance of Water Density in Specific Gravity

Details: Water's density at 4°C (39°F) is used as the reference point (1.000 g/cm³) for all specific gravity measurements. The lb/in³ value allows conversions in imperial units.

4. Using the Calculator

Tips: Enter the material's specific gravity (e.g., 2.65 for quartz, 7.87 for iron) to calculate its density in lb/in³.

5. Frequently Asked Questions (FAQ)

Q1: Why is water's density important for specific gravity?
A: Specific gravity is defined as the ratio of a material's density to water's density, making water's value the fundamental reference.

Q2: Does temperature affect this calculation?
A: The 0.036127 lb/in³ value is for standard conditions (4°C). For precise work at other temperatures, use adjusted water density values.

Q3: How do I find a material's specific gravity?
A: Specific gravity values are published for common materials, or can be measured by comparing weights in air and water.

Q4: What's the difference between density and specific gravity?
A: Density has units (like lb/in³), while specific gravity is a dimensionless ratio relative to water.

Q5: Can I use this for gases?
A: Yes, but gas specific gravity is typically referenced to air (density 0.0000445 lb/in³) rather than water.