Physical Properties of Bronchial Secretion

Abstract

The apparatus used to estimate apparent viscosity should be applicable over a range of applied shear. The basic capillary viscometers which are intended for Newtonian, constant-viscosity materials are not suitable here. The type of apparatus most commonly used for the investigation of the viscosity of biological materials is the rotational viscometer. Most of the apparatus used today is based on Couette’s model. The need for more precise rheological data and advances in engineering and electronics have produced a range of instruments which have been used for the study of biological materials. They include the Rotovisco (Stresemann, 1968) Bruce and Kumar, 1968; Bamberg, 1968; Kinghorn and Addis, 1968) and the Merrill-Brookfield instruments (Sheffner, et al., 1964; Liebermann, 1968, Aiache, et al., 1970). These instruments are extremely useful for determining viscosity at relatively higher shear rates, but do not permit detailed examinations to be carried out at low applied shear.