State primary special standard of the unit of heat quantity in the fi eld of solution and reaction calorimetry GET 133-2023

Abstract

The article shows the need to develop methods and tools for realization and transferring a unit of heat quantity in the fi eld of measuring small thermal effects of physical and chemical interactions  by the method of isothermal titration calorimetry. The relevance of the work is due to the wide application of measuring instruments implementing this method and the lack of standardized metrological procedures and tools. To solve the problem of ensuring unity and traceability of measurements in this fi eld, VNIIM calorimetry laboratory conducted research to expand the functional and measuring capabilities of the State primary special standard of the unit of heat quantity in the fi eld of solution and reaction calorimetry GET 133-2012. In the course of work a reference titration microcalorimeter MKT was developed, investigated, and included in the GET 133-2012. Microcalorimeter MKT was designed to realize, store, and transfer a unit of heat quantity in the fi eld of measuring small thermal effects in liquid media. As a result of microcalorimeter studies, the capability of realizing and transferring a unit of heat quantity in a new range was confi rmed: from 100 to 5000 μJ with an expanded uncertainty from 1.2 to 8.6 %. The improved GET 133-2012 with an updated composition and new metrological characteristics was approved as the State primary special standard of the unit of heat quantity in the fi eld of solution and reaction calorimetry GET 133-2023. This lays the foundations for the creation of new metrological tools and procedures for transferring the unit of heat quantity in the fi eld of solution and reaction calorimetry.