Abstract: In a method for continuous or discontinuous measurement of shear and strain viscosities of Newtonian and non-Newtonian liquids, in particular structurally viscous liquids such as polymer melts and solutions and elastomers as well as other structural liquids, the liquid is passed through a first capillary or capillary configuration and through a second capillary connected in series therewith, wherein the liquid in the first capillary or capillary configuration shears only within a defined shear velocity range and the shear viscosity is determined, and, subsequently, the liquid in the second capillary having the same or somewhat smaller shear velocity range, shears and is additionally subjected to a strain-flow so that its flow-through resistance comprises shear as well as strain resistances.

Abstract: A capillary rheometer for measuring the viscosity of a liquid contained in a vessel in either a continuous or discontinuous fashion provides timely and accurate measures of viscosity. Pressure sensing means are disposed at one or both ends of a capillary. The capillary is fed fluid by a metering pump, which in turn is fed fluid by a supply pump, the inlet of which is configured for attachment with a fluid sampling port of the vessel and the outlet of which is configured to return sample fluid which was not directed through the capillary back to the liquid or the vessel respectively. The output end of the capillary may be connected to a pump for withdrawing fluid from the capillary. The supply pump and the metering pump may be adjusted independently of each other.