A computer-interfaced falling ball viscometer.
We have developed a system that greatly facilitates viscosity measurement under low-shear conditions, based upon a falling ball viscometer interfaced to a personal computer. Three optical sensors indicate the rate of passage of a steel ball falling through a micro-capillary tube, and a potentiometer detects the angle of the tube. The resulting data are passed from a custom program with a graphical user interface to a spreadsheet. The spreadsheet then calculates and stores a value for the viscosity of the sample, using the data passed to it from the viscometer, and a look-up table of stored slope and intercept values calculated from precision viscosity standards. We used the viscometer to determine the kinetics of actin polymerization, and to measure the viscosity of F-actin-aldolase gels. This system provides significantly greater reproducibility and speed in data acquisition than does the traditional 'eyeball and stopwatch' method, and data reduction is virtually instantaneous.
Center for Bioengineering, University of Washington, Seattle, 98195.
J
J
Wang
F
F
Reitz
T
T
Donaldson
L
L
Pagliaro
D000199:Actins / Q000737:chemistry; D000818:Animals; D001704:Biopolymers; D002627:Chemistry, Physical / Q000295:instrumentation*; D011817:Rabbits; D015203:Reproducibility of Results; D012984:Software; D014584:User-Computer Interface; D014783:Viscosity
D000199:Actins; D001704:Biopolymers