Bilateral comparison between viscosity measurement standard systems developed by KRISS and PTB

Abstract

The viscosity measurement standard systems developed by the Korea Research Institute of Standards and Science (KRISS) and Physikalisch–Technische–Bundesanstalt (PTB) were compared, and the international equivalence of the standard viscosity measurement system built by KRISS was confirmed. In the system developed by KRISS, the measurement range of the viscosity measurement standard system was 0.3–100000 mm2/s with 0.17–0.5% uncertainty (U, k = 2). The density of a liquid was measured using a pycnometer, and an absolute viscosity of 0.3–8000 mPas was measured with an uncertainty of 0.18–0.6%. The viscosity measurement standard systems of KRISS and PTB were bilaterally compared, using three different viscosity standard liquids synthesized by PTB, under six experimental conditions. Considering the uncertainty, the calculated En was < 1 (0.17–0.72) for all experimental cases. Therefore, we confirmed the viscosity standard system created recently by KRISS to be significantly equivalent to that developed by PTB.