Specific Gravity has a wide range of applications including: Other instruments to measure specific gravity are the Pycnometer, and digital density meters based on oscillating U-tubes. The device is designed to float freely at the liquid surface with a protruding stem giving a reading corresponding to the specific gravity of the liquid. The hydrometer can be used to measure the specific gravity of any liquid. There is a wide range of instruments designed to measure the specific gravity of a material. The reference density of water at 4 oC (39 oF) is used as the reference as these are the conditions of maximum density. Where SG = specific gravity, ρ = density of the material (kg/m 3), ρW = density of water ( kg/m 3). The following formula is used to calculate the specific gravity of a material. The specific gravity of all other materials is compared to water as a fraction heavier lighter or heavier density. The specific gravities of gases usually are compared to dry air which generally has a density of 1.29 g per litre. By definition, water has a density of 1 kg per litre at this temperature. 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 39.2 degrees Fahrenheit. Specific gravity is unique to every material and has a very wide range of application. 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.
Otherwise, we would have 10 hours/day, 100 minutes/hour, and 100 seconds/minute.Įdit: And what is with 360 degrees instead of 100? Of course that would have changed the Nautical mile.The Specific Gravity of liquids and solids is defined as a dimensionless unit which is the ratio of density of a material to the density of water at a given temperature, where density is defined as the material’s mass per unit volume and is measured in kg/m 3.
It is too bad that the availability of time pieces was so widespread in the 1700s. Time itself is another victim of bad timing. The Nautical mile is probably the only pre-Metric unit that will survive, at least as long as anyone remembers how to navigate beyond looking at a GPS. The Nautical mile was also based on natural or earth units and was no less precise than they were capable of measuring the length of a meridian in those days. It is more complex than that and an interesting story but that was the net effect. That delay significantly hurt the promoters in the early US government that were pushing the metric system. The worse part was the lame attempt to survey that meridian delayed the definition of the Meter by years. It ended up being inaccurate and had to be redefined a few times anyway. They should have used a decimal fraction of a Nautical Mile instead of one ten-millionth of the distance between the North Pole and the Equator along the meridian through Paris. In hindsight, the Meter, or Metre, was really a mistake. It was just bad timing and the distance between markets. The irony is the US is still suffering from the units that you Brits stuck us with! Just joking.