Origin of hydrometerhydro- + -meter
an instrument for measuring the specific gravity of liquids: it is a graduated, weighted tube that sinks in a liquid up to the point determined by the density of that liquid
An instrument used to determine specific gravity, especially a sealed, graduated tube, weighted at one end, that sinks in a fluid to a depth used as a measure of the fluid's specific gravity.
- hy′dro·met′ric hy′dro·met′ri·cal
An instrument used to measure the density of a liquid as compared to that of water. Hydrometers consist of a calibrated glass tube ending in a weighted glass sphere that makes the tube stand upright when placed in a liquid. The lower the density of the liquid, the deeper the tube sinks.
- 89) as follows: - Baume's Hydrometer for Spirits.
- The hydrometer is said by Synesius Cyreneus in his fifth letter to have been invented by Hypatia at Alexandria,' but appears to have been neglected until it was reinvented by Robert Boyle, whose "New Essay Instrument," as described in the Phil.
- The first important improvement in the hydrometer after its reinvention by Boyle was introduced by G.
- Three types of areometer are in use: (I) the ordinary hydrometer of invariable weight with a direct reading scale, a set of from five to ten being necessary to cover the range of specific gravity from 1 000 to 1.031 so as to take account of sea-water of all possible salinities; (2) the " Challenger " type of areometer designed by J.
- Of liquid dis placed) when the surface of the liquid in which the hydrometer floats coincides with the lowest division of the scale, A the area of the transverse section of the stem, 1 the length of a scale division, n the number of divisions on the stem, and W the weight of the instrument.