Hydrometers

Hydrometers measure the density or specific gravity of liquids. A hydrometer works by floating in a liquid and measuring how deeply it sinks. The point where the liquid surface meets the graduated scale indicates the relative density of the liquid compared with water, commonly referred to as specific gravity.

Hydrometers are used in many industries and testing environments where liquid density provides useful information about chemical composition or concentration.

1 product

Liquid Density Measurement for Laboratory and Industrial Applications

Hydrometers are among the simplest instruments for measuring specific gravity or liquid density, which is the ratio between the density of a liquid and the density of water.

The instrument typically consists of a sealed glass tube with a weighted bulb at one end and a narrow stem marked with a graduated scale. When placed in a liquid, the hydrometer floats upright, and the depth at which it settles indicates the liquid’s density.

Hydrometers can be calibrated for a variety of specialised uses. Examples include:

  • Alcohol hydrometers used in brewing and distilling
  • Brix hydrometers for measuring sugar concentration in juices or wine
  • Lactometers for testing the density of milk
  • Battery hydrometers used to test electrolyte strength in lead-acid batteries

Because liquid density changes with temperature and composition, hydrometers are commonly used for quality control, process monitoring and laboratory testing.

Thermometer Superstore offers a range of hydrometers designed for accurate measurement of liquid density in professional, laboratory and industrial environments.

Liquid Density & Specific Gravity Measurement

What is a hydrometer?

A hydrometer is an instrument used to measure the density or specific gravity of a liquid, which helps determine its composition or concentration.

How does a hydrometer work?

A hydrometer works by floating in a liquid. The depth at which it floats depends on the liquid’s density, denser liquids cause the hydrometer to float higher, while less dense liquids allow it to sink further.

What are hydrometers used for?

Hydrometers are used in a variety of applications including brewing, winemaking, laboratory testing, battery maintenance and industrial liquid analysis.

What does specific gravity mean?

Specific gravity is the ratio of a liquid’s density compared with the density of water. Hydrometers measure this value to indicate the concentration or composition of the liquid.

Are there different types of hydrometers?

Yes. Different hydrometers are calibrated for specific uses, including alcohol hydrometers, lactometers for milk, salinometers for salt solutions and Brix hydrometers for sugar concentration.