Calibration of Hydrometers

Can you trust your hydrometer?

After a survey carried out several years ago, we estimated that less than 1% of all hydrometers in use in the UK have a traceable calibration certificate. Uncalibrated hydrometers may give wrong results, which can compromise quality control, and lead to problems with accreditation authorities. Over the years we have received several hydrometers for calibration which had the wrong paper scale inside them, and were about 50 kg/m³ (0.05 g/ml) in error.

In order to maintain the quality of your results, we recommend that hydrometers which are used at ambient temperature are calibrated when new, and thereafter at least once every two years. Hydrometers used far above or below ambient temperature should be calibrated annually.

H&D Fitzgerald offer a comprehensive hydrometer calibration service. All our calibrations are covered by our ISO 17025 accreditation, and we supply a UKAS calibration certificate.

Our calibration service offers:

  • Calibration within the density range 550-2800 kg/m³ (0.55-2.80 g/ml).
  • Best Calibration and Measurement Capability (CMC) of ±0.05kg/m³ ( 0.00005g/ml). The actual CMC quoted on the certificate will depend on the type of hydrometer and its density range.
  • Calibration at any temperature and surface tension you specify.
  • A UKAS calibration certificate, linking your calibrated hydrometer with recognised national standards. (Example certificate)
  • Standard four point calibration. Additional calibration points can be accommodated.

We can calibrate almost any hydrometer, whether it is glass, metal, or plastic, and this includes saccharometers, lactometers, vinometers, brinometers, and marine survey.

For further details and ordering information, see Ordering Hydrometer Calibrations.

For more information about the concept of calibration, see our paper on adjustment and calibration.