Schematic drawing of a hydrometer. The lower the density of the fluid, the deeper the weighted float B sinks. The depth is read off the scale A.
A hydrometer or lactometer is an instrument used for measuring density or relative density of liquids based on the concept of buoyancy. They are typically calibrated and graduated with one or more scales such as specific gravity.
A hydrometer usually consists of a sealed hollow glass tube with a wider bottom portion for buoyancy, a ballast such as lead or mercury for stability, and a narrow stem with graduations for measuring. The liquid to test is poured into a tall container, often a graduated cylinder, and the hydrometer is gently lowered into the liquid until it floats freely. The point at which the surface of the liquid touches the stem of the hydrometer correlates to relative density. Hydrometers can contain any number of scales along the stem corresponding to properties correlating to the density.
Hydrometers are calibrated for different uses, such as a lactometer for measuring the density (creaminess) of milk, a saccharometer for measuring the density of sugar in a liquid, or an alcoholometer for measuring higher levels of alcohol in spirits.
The hydrometer makes use of Archimedes' principle: a solid suspended in a fluid is buoyed by a force equal to the weight of the fluid displaced by the submerged part of the suspended solid. The lower the density of the fluid, the deeper a hydrometer of a given weight sinks; the stem is calibrated to give a numerical reading.
A hydrometer or lactometer is an instrument used for measuring density or relative density of liquids based on the concept of buoyancy. They are typically...
a hydrometer. This consists of a bulb attached to a stalk of constant cross-sectional area, as shown in the adjacent diagram. First the hydrometer is...
referred to as being in 'degrees'. API gravity is graduated in degrees on a hydrometer instrument. API gravity values of most petroleum liquids fall between...
methods such as texture by feel, and quantitative methods such as the hydrometer method based on Stokes' law. Soil texture has agricultural applications...
performed using a hydrometer, and converting the density measurement to extract, the mass fraction of sugars in the wort or beer. Hydrometers can be calibrated...
The Fahrenheit hydrometer is a device used to measure the density of a liquid. It was invented by Daniel Gabriel Fahrenheit (1686–1736), better known for...
Certain ships of the United States Navy adopted the use of the hydrometer in the 1850s. Readings taken of the density of seawater contributed to research...
during the battery life. Some battery manufacturers include a built-in hydrometer to show the state of charge of the battery. The primary wear-out mechanism...
immortalised in an Act of Parliament: Sikes' Hydrometer Act 1816 (56 Geo. 3. c. 140). From 1816 until 1980 the hydrometer was the standard used in the UK to measure...
grain size distribution of fine-grained soils, the hydrometer test may be performed. In the hydrometer tests, the soil particles are mixed with water and...
measurement of density of materials. Such techniques include the use of a hydrometer (a buoyancy method for liquids), Hydrostatic balance (a buoyancy method...
estimated by measurement of specific gravity using a hydrometer or pycnometer. In modern times, hydrometers are still widely used, but where greater accuracy...
temperatures and weather reports are still broadcast in Fahrenheit. Fahrenheit hydrometer People from Gdańsk (Danzig) Anders Celsius Chisholm, Hugh, ed. (1911)...
[citation needed] A more reliable method is to use an alcoholmeter or hydrometer. A hydrometer is used during and after the fermentation process to determine...
a temperature of 293.15 K [20.00 °C; 68.00 °F]. It replaced the Sikes hydrometer method of measuring the proof of spirits, which had been used in Britain...
gradation is determined by analyzing the results of a sieve analysis or a hydrometer analysis. The process for grading a soil is in accordance with either...
of sugar in water is greater than the density of alcohol in water. A hydrometer is used to measure the change in specific gravity (SG) of the solution...
commentary on Book III of the Almagest. Hypatia constructed astrolabes and hydrometers, but did not invent either of these, which were both in use long before...
The Twaddell scale is a hydrometer scale for reporting the measured specific gravity of a liquid relative to water. On this scale, a specific gravity of...
classification Atterberg limits California bearing ratio Direct shear test Hydrometer Proctor compaction test R-value Sieve analysis Triaxial shear test Oedometer...
classification Atterberg limits California bearing ratio Direct shear test Hydrometer Proctor compaction test R-value Sieve analysis Triaxial shear test Oedometer...
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