Relative density:

The ratio of the weight of a given volume of a substance at a given temperature to the weight of an equal volume of a standard substance at the same temperature.

For example, if 1 cubic inch of water at 39 degrees f weighs 1 unit and 1 cubic inch of another solid or liquid at 39 degrees f weight 0.95 unit, then the relative density of the substance is 0.95.

In determining the relative density of gases, the comparison is made with the standard of air or hydrogen.

2.

The ratio of the mass of a given volume of a substance to the mass of a like volume of a standard substance, such as water or air.

3.

The ratio of the density (mass of a unit volume) of a substance to the density of a given reference material.

Specific gravity usually means relative density with respect to water.

The term “relative density” is often preferred in modern scientific usage.

Terms Related to Relative density

• Density

  The mass or weight of a substance per unit volume. For instance, the density of a drilling mud may be 10 pounds per gallon (ppg), ...

• Gravity – specific

  Density expressed as the ratio of the weight of a volume of substance to the weight of an equal volume of another standard substance. In ...

• Barite

  1. Barium sulfate; a mineral frequently used to increase the weight or density of drilling mud. Its relative density is 4.2 (or 4.2 times denser ...

• Specific heat

  The amount of heat required to cause a unit increase in temperature in a unit mass of a substance, expressed as numerically equal to the ...

• Mud density

  Weight per unit volume of drilling fluid usually expressed in pounds per gallon or pounds per cubic foot. See hydrostatic pressure.

• Specific gravity

  See relative density

• Density contrast (seismic)

  Density of one rock relative to another. The contrast can be positive or negative. Gravity anomalies within sedimentary sections can be analyzed as structural or ...