The Margules Method of Measuring Viscosities Modified to Give Absolute Values

Abstract

Measurement of absolute viscosities. A method for determining absolute viscosities in a Margules rotating cylinder type viscometer, without the aid of calibrating liquids of known viscosities, is described. This method involves the determination of true viscosity by extrapolating apparent viscosities for several lengths of inside cylinder to that viscosity corresponding to infinite length. By this method the viscosity of the commercial castor oil used is found to be 9.99 poises at 20°C, and 4.61 poises at 30°C, as compared with 9.86 and 4.51 poises quoted in the Smithsonian Tables for pure oil at corresponding temperatures.