Thermometer Calibration

To complement our production facilities, a comprehensive thermometer calibration service is available for temperature instruments. We offer a UKAS accredited thermometer calibration certification service and also a factory certification service for pressure gauges and hydrometers.

An efficient service is provided to examine and calibrate customers' instruments in addition to supplying new, calibrated thermometers. All instruments are checked regarding accuracy and suitability prior to calibration, but in addition customer instruments can also be examined in detail to confirm they are free of any defects, and ensure they conform to the current revision of the BS, IP or ASTM specification. Customers are advised of any non-conforming instruments they have submitted, prior to thermometer calibration.

Changes of Thermometer Calibration and Re-certification

Secular changes can occur as the bulb glass stabilises, particularly in the first 1-2 years after manufacture. These changes can be monitored by regular verification of the ice-point only, thus avoiding the expense of a complete thermometer calibration certificate. BS 1041 Section 21 (Guide to selection and use of liquid-in-glass thermometers) recommends such checks should take place annually and a complete re-calibration is carried out at intervals of no more than 5 years. Thermometer calibration frequency is the decision of the individual customer and should be based on the environment in which the instrument is used, the frequency of use, any evidence of changes in trends in calibration data, and the level of confidence required in the readings.

Calibration Temperatures

It is preferable for the customer to consider what temperatures thermometer calibration should be performed at and specify this at the time of order. They may be specific points used in a test or a range over which the instrument may be used. The number of points checked will also be determined by the intended application. If the thermometer is used to check a single point (eg 10°C), the only that point need be checked. It may be preferable to select a small range around a single point. When selecting a range, a minimum of 3 points should be specified. Where the customer does not request specific test points, thermometer calibration will be carried out at 5 evenly spaced temperatures covering a minimum of 80% of the instrument's scale and will generally include zero. Calibration points at the extremities of the scale are not recommended as recorded values may sometimes fall outside the scale of the tube.

Suitable Thermometers for Certification

It is recommended that mercury thermometers for certification should be selected from instruments which conform to a recognised standard. These standards can also provide thermometers which are suitable for use as sets comprising a number of instruments which together cover a wide temperature band in subdivisions of 0.2°C or 0.01°C. Examples are BS 593 series A or series B or a selection from series F; ASTM types 37C to 42C (equivalent to IP 77C to 82C) and ASTM 62C to 68C

Our prices for a calibrated thermometer are competitive and we also offer quantity discounts. Please contact us to discuss your requirements.