What does hydrometry mean?
Hydrometry is the scientific measurement of a liquid's density or specific gravity, usually with an instrument called a hydrometer. A hydrometer floats at different depths in liquids of different densities, allowing their composition or concentration to be estimated. The term is used in chemistry and laboratories, as well as in industries such as brewing, food production, petroleum refining, and quality control. Hydrometry can help determine whether a liquid is pure, whether a solution has been prepared at the correct concentration, or whether contamination has occurred. Although the word begins with the same root as “hydrogen” and “hydrology,” its meaning is specifically associated with the physical measurement of liquids. It is more precise than a general reference to measuring density and should not be confused with the instrument itself, which is called a hydrometer.
nounThe measurement of the density or specific gravity of a liquid, especially by means of a hydrometer. It is used in fields such as chemistry, brewing, petroleum processing, and quality control.
- The measurement of the density or specific gravity of a liquid.
"Careful hydrometry revealed that the sample was less dense than the surrounding seawater."
"Routine hydrometry showed that the oil had been contaminated with water."
"The laboratory uses hydrometry to verify the concentration of industrial solvents."
Rare in general use; the plural is chiefly appropriate when referring to distinct acts, methods, or sets of measurements.
"The two hydrometries produced slightly different density estimates."
A hydrometer reveals a liquid's density by floating at a characteristic depth, turning an invisible property into a readable measurement.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of hydrometry
Hydrometry was formed in the early 19th century from Greek hudōr, meaning “water,” and metron, meaning “measure.” Its components also underlie several English words concerning water, including hydrogen, hydrology, and hydraulics. Although the name specifically mentions water, the method is applied to many kinds of liquid.
Related word forms
How hydrometry is actually used
This is a technical term used chiefly in science and industry. In modern usage it usually refers to the measurement of liquid density or specific gravity rather than the general measurement of water.
Easily confused with hydrometry
Hydrometry is the process of measuring a liquid's density or specific gravity, whereas a hydrometer is the instrument used to make that measurement.