Comparison tests for plasma viscosity measurements

The present study measured plasma viscosity using three different viscometers: Ostwald capillary-tube viscometer, Brookfield rotating viscometer, and scanning capillary-tube viscometer (SCTV). The plasma viscosity data obtained using Ostwald viscometer at 37 °C with the conversion constant provided by its manufacturer were in good agreement with those obtained using Brookfield viscometer at 37 °C. In addition, the plasma viscosity data obtained using SCTV were in excellent agreement with those from Brookfield viscometer. However, when the Ostwald viscometer is used for plasma viscosity measurements at the room temperature, one should be cautioned because the conversion constant provided by manufacturers may not be applicable to the room temperature as the surface tension of plasma depends on temperature, affecting the accuracy of the plasma viscosity measurement.