Patent Document ID: 4637250
Application ID: 06694747
Patent Flag: 1

Claim One:
1. An apparatus for the determining viscosity of fluids comprising: a. A cylinder, of diameter D cm., for holding the fluid for which the viscosity is to be determined; b. Means for measuring axial displacement a predetermined distance, L cm., along the vertical axis of the cylinder, remote from the top and bottom by a distance of at least D cm.; c. A needle, made of tubing with rigid side walls the density of which can be adjusted with thin metal wiring to produce a velocity of fall of almost 0 to about 10 cm. per sec. and sealed hemispherically at both ends, having a diameter d cm., wherein b=D/d is at least 5, and a length of l cm., wherein l/D is at least 2.5; d. Means engaging the top of the cylinder for guiding said needle so that the needle will fall along the axis of said cylinder; e. Means for maintaining a constant temperature in the cylinder; and f. Device for measuring the time of fall of the needle between the predetermined distance marked on the cylinder.