specific gravity - mephistolessiveur.info
This calculator will compare the substance density you have entered with the density of pure water and display the result as a specific gravity decimal ratio. Density is defined as mass per unit volume; it has the SI unit kg. m-3 and is an absolute quantity. Specific gravity is the ratio of a material's density with that of. Relative density, or specific gravity, is the ratio of the density of a substance to the density of a . For true (in vacuo) relative density calculations air pressure must be considered (see below). Temperatures are specified by the notation (Ts/Tr).
The temperature and pressure of both the material and water need to be the same as these factors influence the density and hence the specific gravity. Specific gravity is unique to every material and has a very wide range of application.
In more general terms specific gravity is the ratio of the density of a material to that of any standard substance, although usually this is water at 4 degrees Celsius or By definition, water has a density of 1 kg per litre at this temperature. The specific gravities of gases usually are compared to dry air which generally has a density of 1. The specific gravity of all other materials is compared to water as a fraction heavier lighter or heavier density.
How to Convert Density to a Specific Gravity | Sciencing
Calculating Specific Gravity The following formula is used to calculate the specific gravity of a material. The reference density of water at 4oC 39oF is used as the reference as these are the conditions of maximum density.
Measuring Specific Gravity There is a wide range of instruments designed to measure the specific gravity of a material. The hydrometer can be used to measure the specific gravity of any liquid. Temperature dependence[ edit ] See Density for a table of the measured densities of water at various temperatures. The density of substances varies with temperature and pressure so that it is necessary to specify the temperatures and pressures at which the densities or masses were determined.
Relative density - Wikipedia
It is nearly always the case that measurements are made at nominally 1 atmosphere For true in vacuo relative density calculations air pressure must be considered see below. Here temperature is being specified using the current ITS scale and the densities  used here and in the rest of this article are based on that scale.
The temperatures of the two materials may be explicitly stated in the density symbols; for example: Uses[ edit ] Relative density can also help to quantify the buoyancy of a substance in a fluidor determine the density of an unknown substance from the known density of another. Relative density is often used by geologists and mineralogists to help determine the mineral content of a rock or other sample. Gemologists use it as an aid in the identification of gemstones.
Water is preferred as the reference because measurements are then easy to carry out in the field see below for examples of measurement methods.