Hydrometer calibration system

Density calibrator

Hydrometer calibration system

The DM-01 is an automated hydrometer calibration system based on Cuckow’s method or hydrostatic weighing. A temperature bath with stability and uniformity better than 0.01K is located on a base plate whose vertical position is adjusted automatically. A cylinder with calibration liquid inside is immersed into the bath so that the temperature of the calibration liquid is extremely stable up to 0.004K. The hydrometer to be calibrated is immersed partially into the calibration liquid and suspended to a mass sensor, such as balance or mass comparator, which is separately fixed on a vibration free framework. By adjusting the position of the bath, the length or the scale of the hydrometer immersed into the calibration liquid is adjusted precisely, and the mass difference of the hydrometer in the liquid and in the air is measured by the mass sensor. Based on the mass difference, the hydrometer is calibrated with specified uncertainty which is influenced by the solid reference, the temperature stability, the calibration liquid, the atmospheric pressure, the humidity, and so on.

With software DMSo, the calibration is processed automatically, and the calibration result is automatically reported.

DM-01 can be configured as a manual system, or a semi-automatic system, when the DMSo and some parts are not fully integrated.

APPLICATIONS

• As primary standard in NMIs for hydrometer calibration

• As transfer calibration system in metrology institutes or calibration centres

KEY FEATURES

• Automatic calibration process

• Traceability to SI units

• Calibration of all hydrometers with option sinkers

SPECIFICATIONS

• Temperature: 15 to 25°C, extended temperature optional

• Stability and uniformity of the bath: ±0.01K

• Stability of the calibration liquid: ±0.004K

• Calibration liquid: tridecane, options are available

• Mass sensor range: 250 g, options are available

• Mass sensor readability: 0.01mg, options are available

• Solid reference: silicone sphere, other materials are available

• Scale and liquid surface positioning: optical sensor

• Sinkers: optional

• Vibration isolation module and ventilation isolation cabinet are available as options