Hydrostatic Weighing


Also found in: Dictionary, Thesaurus, Medical.

hydrostatic weighing

[‚hī·drə′stad·ik ′wā·iŋ]
(fluid mechanics)
A method of determining the density of a sample in which the sample is weighed in air, and then weighed in a liquid of known density; the volume of the sample is equal to the loss of weight in the liquid divided by the density of the liquid.

Hydrostatic Weighing

 

a method of measuring the density of liquids and solids, based on Archimedes’ law. The density of a solid is determined by weighing it twice—first in air and then in a liquid whose density is known (usually distilled water). During the first weighing the weight of the object is determined. The difference between the results of the two weighings determines the volume of the object.

In measuring the density of a liquid an object—usually a glass float whose weight and volume are already known—is weighed in the liquid. Depending on the degree of accuracy required, hydrostatic weighing is done on technical, analytical, or standard balances. For weighing massive objects less accurate balances are widely used, which facilitate quicker measurement (for example, the Mohr balance).

REFERENCE

Kivilis, S. S. Tekhnika izmereniia plotnosti zhidkostei i tverdykh tel. Moscow, 1959. Chapter 4.
Kivilis, S. S. Izmerenie massy, ob’ema i plotnosti. Moscow, 1972. Chapter 26.

S. S. KIVILIS

References in periodicals archive ?
Thus the corrected Tanita measurements are a likely replacement for hydrostatic weighing.
The corrected athletic mode was used as a replacement for hydrostatic weighing for determining the correct categorization.
More precisely, the Tanita athletic mode algorithm can be corrected as a practical replacement for hydrostatic weighing.
The densities of the prototype kilograms K20 and K4 have been measured at the BIPM using hydrostatic weighing techniques with water as a reference standard; the measured values are 21 539.
Prior to the mass calibration, the densities are determined using the hydrostatic weighing method with silicon reference standards, as described above.
Other equations using these or additional skinfold measurements have been proposed, though comparative studies with hydrostatic weighing have found the methods of Lohman and Brozek to have the best predictive ability.
Reliability of hydrostatic weighing and skinfold measurements of body composition using a generalizability study.
Another study compared the same equation to the criterion measures of DEXA and hydrostatic weighing (5).
14) compared DEXA, hydrostatic weighing, and air displacement plethysmography to a multi-compartment model in NCAA Division I female athletes.