## What is the principle of specific gravity?

Archimedes’ principle states that the buoyant force on an object equals the weight of the fluid it displaces. Specific gravity is the ratio of the density of an object to a fluid (usually water).

What is the purpose of specific gravity test?

Significance and Use Knowing the specific gravity will allow determination of a fluid’s characteristics compared to a standard, usually water, at a specified temperature. This will allow the user to determine if the test fluid will be heavier or lighter than the standard fluid.

How does hydrometer measure density?

A hydrometer is an instrument used to measure the specific gravity (or relative density) of liquids; that is, the ratio of the density of the liquid to the density of water. A hydrometer is usually made of glass and consists of a cylindrical stem and a bulb weighted with mercury or lead shot to make it float upright.

### How does specific gravity work?

The specific gravity of an object is the ratio between the density of an object to a reference liquid. The specific gravity has no units. If the specific gravity has a value of greater than one, then the object sinks in water and if it is less than one, then the object floats in water.

Why is it called specific gravity?

The correct (and more meaningful) term is relative density. Why specific? Usually specific means that the quantity does not depend on how much you consider, if you take 1 L of ethanol or 2 liters – they have the same SG because you need to compare it with the same amont of water and the volume goes away in the ratio.

Is density specific gravity?

Density is defined as mass per unit volume. Specific gravity is the ratio of a material’s density with that of water at 4 °C (where it is most dense and is taken to have the value 999.974 kg m-3). It is therefore a relative quantity with no units.

#### What is the principle of hydrometer?

A hydrometer is an instrument used to determine specific gravity. It operates based on the Archimedes principle that a solid body displaces its own weight within a liquid in which it floats. Hydrometers can be divided into two general classes: liquids heavier than water and liquids lighter than water.

What is specific gravity in simple words?

Specific Gravity (SG) is a special case of relative density. It is defined as the ratio of the density of a given substance, to the density of water (H2O). Substances with a specific gravity greater than 1 are heavier than water, and those with a specific gravity of less than 1 are lighter than water.

What instrument measures specific gravity?

A hydrometer is a scientific instrument used to measure both the specific gravity and the density of a liquid, based on Archimedes ’ principle of buoyancy. It is composed of a sealed glass bulb with a long skinny tube connected to one end, and it is weighted with mercury or lead shot under the bulb so it can float upright.

## How do you use a hydrometer?

How To use a Hydrometer. Place the hydrometer in the plastic tube. We personally use the same tube that the hydrometer is shipped in. Using the tube, you have to hold it steady with one hand as you pour in the liquid to be measured with the other hand. Then eye the level the hydrometer floats to.

What is hydro meter?

Hydrometer , device for measuring some characteristics of a liquid, such as its density (weight per unit volume) or specific gravity (weight per unit volume compared with water). The device consists essentially of a weighted, sealed, long-necked glass bulb that is immersed in the liquid being measured;

What do hydrometers test?

A hydrometer is a simple device that allows you to measure the density of various liquids relative to water. Hydrometers are used for a myriad of different purposes: they are used to measure the fat content of milk, the alcohol content of beer, wine, and spirits, and even the water content of urine to test for dehydration.