Quality assurance and test tool monitoring service
Quality assurance of your products is an important component in your company’s success. A recognised quality management system is therefore absolutely essential in the world of measurement and weighing.
HÄFNER can offer its clients an individual concept for outsource service of test tool monitoring for scales and test weights.
National Standard of the Federal Republic of Germany
Scales measure the weight force of an object. This force depends on the location of the scales and reduces the further away the scales are from the centre of the earth. This is why the weight force shown must be synchronised to the mass placed on the scales. This process is known as adjustment.
The mass is the only basic unit that cannot be traced back to a natural constant but rather to a defined unit – the primary kilogram. The primary kilogram is a platinum-iridium cylinder with a diameter of 39 mm and a height of 39 cm. It has a density of 21.5 g/cm³. It is located at the Bureau International des Poids et Mesures (BIPM) in Sèvres near Paris. Every country has an extremely precise ‘national standard’ that is derived from the primary kilogram.
Weights that are used for the adjustment, calibration or testing of scales must be traceable back to the primary kilogram or to a national standard. This ensures that the testing standards in various laboratories coincide.
The traceability is defined as the property of a measurement result or standard that refers to an uninterrupted chain of comparative measurements with given measurement uncertainties to suitable national or international standards and is thus traced to a generally accepted physical base value.
These comparative measurements take place in national metrological institutes, accredited calibration laboratories and at official calibration authorities. Each connection (trace) is documented in a test or calibration certificate in which the determined discrepancy from the nominal value and the measurement uncertainly are recorded.