Abstract: A method of testing the accuracy of results obtained from an automatic viscometer is described. Firstly, provide an automatic viscometer having at least two capillary tube test sections, each of a distinct uniform diameter. Secondly, calibrate the automatic viscometer by allowing a Newtonian fluid of known viscosity to flow through each of the capillary tube test sections and recording the time duration of the flow of the Newtonian fluid through each of the capillary tube test sections. Thirdly, calculate a viscosity constant for each capillary tube test section by dividing the known viscosity by the recorded flow time. Fourthly, send a test sample through each of the capillary tube test sections and record the time duration of the flow of the test sample through each of the capillary tube test sections. Fifthly, calculate values for the viscosity of the test sample based upon the times recorded and the known viscosity constant for each of the at least two capillary tube test sections.