An error analysis of a rheological study of magnetic nanofluids on a rotational viscometer

The paper considers metrological instrumentation for studying the rheological properties of magnetic fluids. It also presents the design of a magnetic coaxial viscometer. There is a metrological analysis of the factors that affect the measurement accuracy. Errors are systematized into 2 main groups: method and instrumental. The authors analyse the contribution of each group to the total metrological error. It is established that the temperature instability of the liquid under study and the error in determining the level of the liquid in contact with the measuring cylinder have the greatest effect on the measurement results. There is a theoretical assessment of the instrument error and its minimum value. The authors propose the main directions for improving the viscometer design. They also show the possibility of a significant reduce in the total measurement error by calibrating the device. There are comparative studies of experimental and reference liquids indicating good accuracy and reliability of experimental data.