Brookfield Falling Ball KF40 - Manual (Page 13)

Brookfield Engineering Labs., Inc. Page 13 Manual No. M11-353-A0512
It is recommended that you record the passage of the lower ball point using the ring marks as
follows. Position your eyes at the same height as the ring marks so that these appear as a line.
A dark paper, placed behind the viscometer with its edge at the same height as the ring mark,
shows the ball periphery more distinctly.
With dark liquids, you can better observe the ball in the sample tube by looking from behind
the instrument.
Possible variations in the measuring times may be due to impurities in the sample, air bubbles or
the fact that it has not been brought to the right temperature (insufficient temperature control).
Even 0.1°C change in temperature is clearly measurable. The first forward and return passage
of the ball can be used to achieve a thorough mixing (temperature equalization) of the sample
before running the viscosity test.
BALL BEGINS
DESCENT
START STOP-
WATCH WHEN
BOTTOM OF
BALL CROSSES
OVER THE
RING MARK
BALL
BALL IN
TRANSIT
AT
MIDPOINT
BALL
FINISHES
DESCENT
STOP STOP-
WATCH WHEN
BOTTOM OF
BALL CROSSES
OVER RING
MARK
RING MARK