Museu Oceanográfico, University of São Paulo 2016 06

A salinometer is a device designed to measure the

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

, or dissolved

salt Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quant ...

content, of a

solution Solution may refer to: * Solution (chemistry), a mixture where one substance is dissolved in another * Solution (equation), in mathematics ** Numerical solution, in numerical analysis, approximate solutions within specified error bounds * Solutio ...

. Since the salinity affects both the

electrical conductivity Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows ...

and the

specific gravity Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its dens ...

of a solution, a salinometer often consist of an

ec meter An electrical conductivity meter (EC meter) measures the electrical conductivity in a solution. It has multiple applications in research and engineering, with common usage in hydroponics, aquaculture, aquaponics, and freshwater systems to moni ...

hydrometer 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 hydromete ...

and some means of converting those readings to a salinity reading. A salinometer may be calibrated in either micromhos, a unit of

, (usually 0-22) or else directly calibrated for salt in 'grains per gallon' (0-0.5). A typical reading on-board ship would be 2 micromhos or 0.05 grains per gallon. A reading of twice this may trigger a warning light or alarm.

Applications

Fresh water generators (

Evaporators An evaporator is a device used to turn the liquid form of a chemical substance, such as water, into a vapor. Uses Air conditioning and refrigeration Some air conditioners and refrigerators use a compressed liquid with a low boiling point, su ...

) use salinometers on the distillate discharge in order to gauge the quality of the water. Water from the evaporator can be destined for potable water supplies, so salty water is not desirable for human consumption. In some ships, extremely high quality distillate is required for use in water-tube boilers, where salt water would be disastrous. In these ships, a salinometer is also installed on the feed system where it would alert the engineer to any salt contamination. The salinometer may switch the evaporator's output from fresh-water to feed-water tanks automatically, depending on the water quality., pp. 212-213 The ''higher'' quality (lower salinity) is required for the

boiler feedwater Boiler feedwater is an essential part of boiler operations. The feed water is put into the steam drum from a feed pump. In the steam drum the feed water is then turned into steam from the heat. After the steam is used it is then dumped to the ma ...

, not for drinking.

References

External links

History of the development of salinometers

Modern oceanographic salinometers
Measuring instruments {{Measurement-stub

Applications

See also

References

External links