Brookfield Falling Ball KF40 - Manual (Page 5)

Brookfield Engineering Labs., Inc. Page 5 Manual No. M11-353-A0512
I. INTRODUCTION
Falling Ball Viscometer, Models KF30 and KF40, comply with the German industry standard
DIN 53015. The measuring principle, according to Höppler, is to determine the falling time of
a ball in a cylindrical glass tube filled with liquid. The working angle of the falling tube in the
KF30 is fixed in the DIN 53015 position of 80° relative to horizontal. The water jacket, sur-
rounding the falling tube, when connected to a Brookfield circulating temperature bath provides
for precise temperature control of the sample.
The user calculates the dynamic viscosity of the sample by determining the falling time of the
ball between the upper and lower ring marks displayed on the falling tube. Using data on the
ball constants, the density difference between the liquid sample and the ball, and the working
angle constant, a mathematical equation is used to convert the time measurement to a viscosity
value in centipoise.
Note: The ball constants (forwards and backwards) and ball densities are listed on the test
certificate accompanying the instrument. You must provide the density value for the
liquid that you are testing.
The six (6) balls with different diameters and densities enable the KF30 to measure a wide range
of viscosities. The ability to adjust the angle of inclination of the KF40 extends the measuring
range for low viscosity liquids.
For non-Newtonian liquids, by subjecting the same sample to repetitive measurements with the
KF40 at different angles, pseudoplastic or dilatant behavior may be determined as explained in
Section 7. Time dependent behavior (thixotropy and rheopexy) may also be noted.
The ease of operation and precise temperature control, using a Brookfield circulating temperature
bath, allows for very reproducible measuring results.
I.1 Components
Component Part No. Quantity
Falling Ball Viscometer: 1
KF30 at fixed DIN position of 80° KF30 -
OR KF40 variable angle with position 80°, 70°, 60° 50° KF40 -
Set of (6) balls with gauge (FB68) in a carrying case (FB22) FB21C 1
Supplied w/certificate stating diameter and mass of each ball
-Ball 1 (glass) FB1 -
-Ball 2 (glass) FB2 -
-Ball 3 (nickel and iron) FB3 -
-Ball 4 (nickel and iron) FB4 -
-Ball 5 (steel) FB5 -
-Ball 6 (steel) FB6 -
Ball Tweezers FB51 1