19. June at 15.15 in UT Senate Hall will defend Riho Vendt his doctoral theses in physics "Combined method for establishment and dissemination of the international temperature scale"
Supervisers: DSc Mart Noorma
DSc Toomas Kübarsepp
Oponents:DSc Martti Heinonen, Centre for Metrology and Accreditation (MIKES), Espoo, Finland
Dr.Eng. Mart Tamre, Tallinn Technical University, Tallinn, Estonia
Combined method for establishment and dissemination of the international temperature scale
Reliability and international equivalence of measurement results are important issues in sustainable operation and development of the modern society. Discrepancies in measurement results have even been identified as one of the major barriers to trade and innovation. It is a common practice that each independent country has established a national measurement infrastructure. In most countries these infrastructures have been developed in a process of scientific research over more than hundred years. Nevertheless new independent countries with evolving economy and needs for a reliable metrology system are still emerging. This was also the case for Estonia, where the development of national standards and measurement scales started only in the 1990-s.
Establishment of a new national measurement standard must be designed carefully for optimal use of limited resources. The study describes establishment and dissemination of the national temperature scale in Estonia with the link to the international temperature scale ITS 90 in the temperature range from 40 °C to +300 °C with approximate expanded measurement uncertainty of 10 mK. The temperature range and uncertainty level originate from the actual needs mapped by a special survey carried out by the Ministry of Economic Affairs and Communications in 2002. The stated uncertainty level is generally larger than usually obtained by primary realizations, but too small to be achieved by secondary methods only. Therefore the temperature scale is established by combining primary and secondary techniques of the ITS 90. The combined method for establishment of the temperature scale is described on the example of Metrosert - the laboratory for national standards in Estonia, but it can be also applied in other laboratories aiming the similar measurement range and capability. The methods described in the study are important as they support wide area of measurement applications including establishment of all officially approved national measurement scales in Estonia.