The technology supplied by Norcross
Corporation employs the Piston Principle of
viscosity measurement. In this technology, a piston
assembly as described in the drawing (at right) is
periodically raised by an air lifting mechanism,
drawing the material being measured down through the
clearance between the piston and the inside of the
cylinder into the space which is formed below the
piston as it is raised. The assembly is then held up
for typically 20 seconds (animation at right has
been set for a 10 second rise). The assembly is then
allowed to fall by gravity, expelling the sample out
through the same path as it entered. The time of
fall is a measure of viscosity, with the clearance
between the piston and inside of the cylinder
forming the measuring orifice. The Norcross
viscosity controller measures the time of fall and
displays the resulting viscosity value.
