GB482950A - Improvements in apparatuses for the measurement of viscosity and thixotropy - Google Patents

Abstract

482,950. Viscosirneters. GOODEVE, C. F. Oct. 6, 1936, No. 27043. [Class 106 (ii)] Apparatus for measuring viscosity and thixotropy consists of inner and outer coaxial cones the distance between the surfaces of which can be varied by axial movement of one relative to the other, and in which the rotation of one of them produces a drag on the other through a fluid placed between them. The Figure shows a form which can be dipped into the liquid to be tested. The outer cone A mounted on ballbearings B is rotated by a motor, not shown, via the gear C. The inner cone E is supported by the tube F and may have its ends hollowed out. The tube F fits into a tube G and is fixed thereto by a set screw H working in a slot J. Movement of the tube F is obtained by turning the nut K, the top of the tube co-operating with a dial on the nut K to indicate the separation of the cones. A dial M co-operates with a pointer N to indicate the angular displacement of the tube G caused by the viscous force on the cone E which is opposed by a clock spring P one end of which is fixed to the inner system and the other end to the casing R. Thixotropy can be measured by allowing time for the liquid to set after the insertion of the apparatus. The motor is then started and the inner cone carried around with the outer until the force exerted by the spring is sufficient to break the thixotropic structure and establish the liquid state. In a modification, the outer cone contains the fluid and fits into a holder with which it is rotated by variable speed gear driven from a motor. The inner cone is fixed to a thermometer tube suspended by a torsion wire. The distance between the cones is adjusted by a screw moving the whole suspension.