National Standard for the Viscosity of Liquids

The National Standard for Viscosity serves to realize and transfer the unit of kinematic viscosity in the range of 4.0 × 10⁻⁷ m²/s to 2.0 × 10⁻¹ m²/s and dynamic viscosity from 4.0 × 10⁻⁴ Pa·s to 200 Pa·s.

Importance of Viscosity Measurement

Viscosity is a crucial technological parameter across various industries. The National Viscosity Standard ensures traceability for viscosity measuring instruments used in:

• Automotive industry
• Pharmaceutical sector
• Chemical and petrochemical industries
• Customs administration
• Slovak Armed Forces
• Certified Reference Materials (CRM) for viscosity

Reference and Realization of Viscosity Unit

• The reference value of kinematic viscosity is based on the tabulated kinematic viscosity of freshly redistilled water under reference conditions.
• The National Standard for Viscosity implements an independent viscosity scale, maintained by only a few national metrology institutes in the EU, including the National Standard of the Czech Republic (ČMI).

Method of Viscosity Realization

1. Kinematic viscosity is determined by measuring the flow time of a precisely defined volume using flow viscometers.
2. Dynamic viscosity is determined using national standard viscometers in conjunction with the National Standard for Liquid Density.
3. Dynamic viscosity is calculated by converting kinematic viscosity (from the Viscosity Standard) and liquid density (from the Density Standard).

Advanced Measurement and Calibration Capabilities

• The measurement setup of the National Viscosity Standard allows for fully automated viscosity measurements.
• Specialized stands and sensors developed at SMÚ enable automatic calibration of customer viscometers directly at the viscometer’s markings.

This National Standard for Viscosity ensures high precision and reliability for viscosity measurements and calibrations, supporting industry, research, and trade at the highest metrological level.

Documents for download

• Osvedčenie (certifikát) (pdf, 1.6 MB)