Improvements in the Use of Falling-Rod Viscometers.

This paper considers the current method of use of falling-rod viscometers. It demonstrates that the normal graphical method of interpreting results with this instrument involves a high error factor which renders the system unsuitable for the specification of litho and letterpress printing inks. Recommendations are made which increase the ease of determination of rheological properties and also or in the accuracy and repeatability of test results to a point where they have value in an ink specification.