State Primary Standards of Density and Dynamic and Kinematic Liquid Viscosities: History of Creation and Modernization

The paper analyzes the current state of metrological infrastructure in the Russian Federation in the field of density and viscosity measurements. GET 17-2018 State Primary Standard of Dynamic and Kinematic Liquid Viscosities and GET 18-2014 State Primary Density Standard are described, as well as their further development, composition, operating principle, and main metrological characteristics. The need to update the State Hierarchy Schemes for instruments measuring density and liquid viscosity is indicated. The authors consider further stages in the improvement of state primary standards of density, as well as dynamic and kinematic liquid viscosities. Promising areas for GET 17-2018 improvement include the automation of measuring processes, i.e., the development of an automatic system for counting the flow time of the examined liquid through the capillary of the viscometer, and the upper limit range expansion for dynamic and kinematic viscosities and pressure up to 100 MPa. The improvement of GET 18-2014 is primarily aimed at creating a basis for the development of metrological support methods for instruments measuring the density of gases, including natural gas, at an excess pressure not exceeding 30 MPa and within the temperature range of 0–100°. The paper presents results obtained in the key comparisons of standards confirming the calibration and measurement capabilities of the Russian Federation in the field of viscosity and density measurements.