A hydrometer is used to measure specific gravities (densities) of liquids. Specific gravity is the ratio of the density of the liquid to the density of pure water.
Hydrometers are usually made up of a glass bulb, containing a quantity of lead shot, attached to a graduated cylindrical stem. The liquid under test is poured into a cylindrical glass vessel then the hydrometer is carefully lowered into it until it floats. The point at which the surface of the liquid lines up with the graduated stem indicates the specific gravity. However care needs to be taken in reading the hydrometer as it is easy to misread the scale. Once the hydrometer has stopped moving up and down observe the point where the liquid makes contact with the graduated stem. Due to surface tension the liquid will form a meniscus on the neck of the hydrometer that is at a slightly higher level than that of the liquid in the cylinder. Take the reading of specific gravity at the level of the liquid not at the level of the meniscus.
Hydrometers should not be subjected to impact such as being dropped as they are easily damaged or become inaccurate.
Hydrometers are important tools with a host of applications. For example they are used to check the strength of the acid in car batteries, they are used to check the creaminess of milk, they are used to check solvents, they used in laboratories and in industry to confirm the effectiveness of processes and they are also used to check the alcohol content in spirits.
Although they are robust, users need to ensure their hydrometers remain in good working order and accurate.
HYDROMETER CALIBRATION PROCEDURE
Hydrometers are first cleaned and then checked to ensure that they are not damaged. They are then examined for accuracy over the range of use in accordance with Australian Standard AS 2026.
CMS uses calibrated state-of-the-art master equipment to verify that hydrometers are measuring within requirements.
Hydrometers are returned to our clients with a comprehensive calibration report within three working days of receipt.
MAKES OF HYDROMETERS WE CALIBRATE
At CMS we calibrate a wide range of hydrometers.
Makes include: – Vee Gee Scientific, Wilkens-Anderson, Thermo-Fisher, Kent Marine, TetraTec and others.
RELATED EQUIPMENT CALIBRATION SERVICES YOU MAY WANT
You may find the following equipment calibration services helpful:
Calibration Management operates in accordance with ISO/IEC 17025:2005 “General Requirements for the Competence of Testing and Calibration Laboratories.”
Please do not hesitate to call Calibration Management on 08 8381 1322 if you have any questions related to equipment calibration – our friendly team will be pleased to assist you.