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This calibration process provides you with a certificate demonstrating the traceability of your standards with respect to the international system of units. The LNE National Metrology Laboratory safeguards the preservation, development and improvement of France's mass unit as well as its transfer to industry.
Proposed calibration services
- Calibration of hydrometers and alcoholometers by hydrostatic method performed at 20°C, simplified method, uncertainty (0.04 g.dm3 + 0.3 e)
- Calibration of hydrometers and alcoholometers by hydrostatic method performed at 15°C, simplified method, uncertainty (0.04 g.dm3 + 0.3 e)
- Calibration of hydrometers and alcoholometers by hydrostatic method performed at 20°C, complete method, uncertainty (0.02 g.dm3 + 0.1 e if l > 1 mm)
- Calibration of hydrometers and alcoholometers by hydrostatic method performed at 15°C, complete method, uncertainty (0.04 g.dm3 + 0.1 e if l > 1 mm)
- Calibration of LPG hydrometers by simplified hydrostatic method performed at 15°C, uncertainty > 0.30 g.dm3
- Calibration of LPG hydrometers by simplified hydrostatic method performed at 15°C, uncertainty < 0.30 g.dm3
Accreditation details
These services are performed under COFRAC Accreditation No. 2-36
List of sites and scopes available on www.cofrac.fr
Additional services
The calibration of glass hydrometers requires knowledge of the characteristics relative to instrument manufacturing or use, namely:
- surface tension of the liquid that the hydrometer is intended to measure,
- the meniscus reading method: in the liquid plane (transparent liquids), or at the top of the meniscus (opaque liquids),
- temperature of the measured liquid.
On new instruments designed for general use, an identification and marking compliant with the specifications of Standard NF B 35-511 are highly advised.
This calibration process is performed according to the hydrostatic method (known as the CUCKOW method) at three points on the scale and at a temperature of either 15°C (petroleum products) or 20°C (general purpose).
Alcoholometers
Alcoholometers are calibrated at 20°C under the same conditions as those of hydrometers. The calibration result is provided in the form of corrections to the alcoholic degree by volume reading.
Thermo-hydrometers
Calibration of the embedded thermometer is performed by LNE's COFRAC-accredited thermometry calibration laboratory, resulting in the issuance of a corresponding calibration certificate.
LPG hydrometers
The complete calibration of a hydrometer for liquefied petroleum gas (LPG) includes individual calibrations of the hydrometer and the embedded thermometer, plus a determination of the influence of pressure on the indications output by both the hydrometer and thermometer.
This determination of pressure influence must be conducted at least once upon initial service startup of the device in order to identify the corrections to be applied for hydrometer calibration and use.
