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Specific Gravity Equation:
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Specific gravity of gas is a dimensionless quantity that represents the ratio of the density of a gas to the density of air at standard conditions. It indicates how heavy or light a gas is compared to air.
The calculator uses the specific gravity equation:
Where:
Explanation: The equation calculates the ratio of molecular weights, which is equivalent to the density ratio for ideal gases at the same temperature and pressure.
Details: Specific gravity is important in various industrial applications including gas flow measurement, pipeline design, combustion processes, and safety considerations for gas handling and storage.
Tips: Enter the molecular weight of the gas in g/mol. The molecular weight of air is pre-set to 28.97 g/mol but can be modified if needed. All values must be positive numbers.
Q1: What does specific gravity tell us about a gas?
A: Specific gravity indicates whether a gas is heavier (SG > 1) or lighter (SG < 1) than air, which affects its behavior in containment and dispersion.
Q2: Why is 28.97 g/mol used for air?
A: This value represents the average molecular weight of dry air, which is primarily a mixture of nitrogen (28 g/mol) and oxygen (32 g/mol).
Q3: How does temperature affect specific gravity?
A: For ideal gases, specific gravity remains constant with temperature changes since both densities change proportionally.
Q4: What are typical specific gravity values for common gases?
A: Natural gas: 0.55-0.70, Propane: 1.52, Butane: 2.00, Hydrogen: 0.07, Carbon dioxide: 1.52.
Q5: When is specific gravity measurement important?
A: It's crucial in gas flow measurement (orifice plates, venturi meters), leak detection, ventilation system design, and safety planning for gas storage facilities.