GB683031A - Improvements in or relating to viscosimeters - Google Patents

Abstract

683,031. Viscosimeters. TEXACO DEVELOPMENT CORPORATION. Dec. 7, 1949, No. 31394/49. Class 40 (i) [Also in Group XIX] A viscosimeter comprises a body 14, Fig. 1, rotated at constant speed in the fluid 16, the container of which is rotatable in relation to its support against a spring 21. The support, which in this embodiment is a graduated table is acted on by a reversible servomotor to keep the tension of the spring equal and opposite to the torque due to the rotation of 14. The position of the container in relation to the fixed framework thus remains substantially constant and the position of the support indicates the viscosity. In modifications, Figs. 2 and 4 (not shown) servo-driven supports operate recording pens directly and via a selsyn link respectively. In a further modification, Fig. 5, the relays 111, 112 controlling the servo-motor 119. instead of being energized directly from a pair of switches as in the arrangements previously described, are operated via a phase-sensitive rectifier and D.C. amplifiers from the output of an A.C. bridge which is unbalanced by movements of copper discs 93, 94 in relation to inductors 96, 95 when the fluid container moves in relation to its support. Hunting is prevented by resistance-capacity combinations 108, 109. In a further modification, Fig. 6 (not shown), the pick-up device includes an eccentrically-mounted magnetic disc co-operating with an E-shaped core carrying a pair of . coils which act differentially on the servo-motor.