With the product line “temperature sensor technology”, JUMO is the leading manufacturer and supplier of temperature sensors manufacturer for heat counters in Europe. The heat meter, like other measurement devices, is used for the billing of goods or services (here heating costs) and thus is subject to the legally binding metrology. In order to be able to be used in commercial operations, the measurement device previously had to have a model authorisation. In the required authorisation test, at first the construction of the device was tested for compliance with the legal requirements and for the measurement stability. After the measurement device had been produced, the correct measurement was tested in a state run testing authority which is independent from the manufacturer. The measurement device did not receive the calibration stamp until then.
It is the goal of the EU economic region to tear down the barriers in trade between the individual European countries through standard rules and regulations. With the European Measuring Instruments Directive (MID) 2204/22/EC, which

entered into effect in all member states of the EU on
30 October 2006, the demands for differing types of measurement devices are harmonised as a basis for fair trade and for the establishment of trust in measurements in the public interest. The previously common calibration stamp was replaced by the CE and the metrology sign, which state that a device which is provided with this sign may be used immediately in all EU states.