Brookfield Falling Ball KF20 User Manual
SPECIALISTS IN THE
MEAS UREMENT AND
CONTROL OF VISCOSITY
TEL508-946-6200
or 800-628-8139 (USA excluding MA)
BROOKFIELD ENGINEERING LABORA TORIES, INC.
11 Commerce Boulevard, Middleboro, MA 02346 USA
with offices in
:
Boston • Chicago • London • Stuttgart • Guangzhou
BROOKFIELD KF10 and KF20
Falling Ball Viscometer
Operating Instructions
Manual No. M09-352-B0411
Brookeld Engineering Labs., Inc. Page 1 Manual No. M09-352-B0411
Table of Contents
I. INTRODUCTION ..............................................................................................................3
I.1 Components .......................................................................................................................................3
I.2 Specications .....................................................................................................................................4
I.3 Details on Viscosity Measurement Range .........................................................................................5
I.4 Description of the Equipment ............................................................................................................5
I.5 Safety Symbols and Precautions .......................................................................................................9
I.6 Cleaning .............................................................................................................................................9
II. GETTING STARTED ...................................................................................................10
II.1 Choice of Balls ...............................................................................................................................10
II.2 Filling the Sample Tube .................................................................................................................10
II.3 Temperature Control of the Sample ...............................................................................................11
II.4 Measuring the Falling Time ...........................................................................................................12
III.CALCULATIONS ..........................................................................................................13
III.1 Dynamic Viscosity ..........................................................................................................................13
III.2 Kinetmatic Viscosity .......................................................................................................................14
IV. DETERMINATION OF THE NON-NEWTONIAN BEHAVIOR ...........................15
IV.1 Thixotrophy/Rheopexy ...................................................................................................................15
IV.2 Structural Viscosity (Pseudoplasticity and Dilantancy) .................................................................15
Appendix A - Maintenance .....................................................................................................16
A.1 Exchanging the Sample Tube ............................................................................................................16
A.2 Exchanging the Water Bath Jacket .....................................................................................................16
A.3 Exchanging the Ball or the Viscometer .............................................................................................16
Appendix B - Calibration of the Ball Constants ........................................................................17
Appendix C - Warranty Repair and Service ..............................................................................18
Brookeld Engineering Labs., Inc. Page 2 Manual No. M09-352-B0411
I. INTRODUCTION
Falling Ball Viscometer, Models KF10 and KF20, 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 lled with liquid. The working angle of the falling tube in the
KF10 is xed in the DIN 53015 position of 80° relative to horizontal. The water jacket, surrounding the falling tube, when connected to a Brookeld 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
certicate 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 KF10 to measure a wide range
of viscosities. The ability to adjust the angle of inclination of the KF20 extends the measuring
range for low viscosity liquids.
For non-Newtonian liquids, by subjecting the same sample to repetitive measurements with the
KF20 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 Brookeld circulating temperature
bath, allows for very reproducible measuring results.
I.1 Components
Component Part No. Quantity
Falling Ball Viscometer: 1
KF10 at xed DIN position of 80° KF10 OR KF20 variable angle with position 80°, 70°, 60° 50° KF20 -
Set of (6) balls with gauge (FB68) in a carrying case (FB22) FB21C 1
Supplied w/certicate 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
Brookeld Engineering Labs., Inc. Page 3 Manual No. M09-352-B0411
Wire Cleaning Brush for Sample Tube FB53 1
Brush to clean loose debris from Falling Balls FB52 1
Leather cloth for polishing Falling Balls FB70 1
Sealant ring (perbunane) A 16x20 FB31 4
Sealant ring (silicone) 10x14x2 FB32 1
Thermometer, 0°C to +100°C* TM1 1
Operator Manual M09-352 1
Instrument Case FB71 1
Latex rubber tubing, 5/16 I.D. x 1/16 wall FB69 1
Certicate of Calibration ____ 1
*Other temperature measurement options are available. Contact your Brookeld dealer for
information.
I.2 Specifications
Viscosity Range: 0.5 - 7x104 mPa•s (cP)
Falling Time-Lower Limit: 60 s for Ball No.1
30 s for Ball Nos. 2,3,4,5 and 6
Falling Time-Upper limit: 300 s
Materials with viscosity >7x104 mPa•s require running
times of over 300 s.
Measuring Distance: 100 mm (50 mm between adjacent ring marks) in both
directions
Fall Tube Inner Diameter: 15.94mm +/- 0.01mm
Set of Balls: 6 balls
Working Angle: KF10: 80° (DIN position)
KF20: 80°, 70°, 60°, 50°
Temperature Range: -60°C - +150°C
Sample Volume: 40 mL
Dimensions: 180 mm x 220 mm x 330 mm
Weight: 6.4 lbs, 2.9 kg
(empty sample tube and empty water jacket)
Brookeld Engineering Labs., Inc. Page 4 Manual No. M09-352-B0411
I.3 Details on Viscosity Measurement Range
Per DIN 53015, the Falling Ball method is suitable for measuring dynamic viscosities ranging
from 0.6 mPa•s to 250,000 mPa•s at temperatures from -60ºC to 150ºC. Use is made of six
balls having different diameters, each ball covering part of the range. All guideline values and
referenced parameters in the following table are per DIN 53015.
Viscosity
Ball
No.
measurement
range (guideline value)
(mPa•s)
Material
(Recommendation)
1 0.5 to 10 Borosilicate
Density
(guideline
value)
3)
(g/cm
Ball diameter
(mm)
Deviation
from
circularity
(mm)
2.4 15.81 ± .01 ± 0.0005 0.007
Calibration
constant
(guideline value)
(mPa•s•cm3/g•s)
glass
2 9 to 140 Borosilicate
2.4 15.6 ± 0.05 ± 0.0005 0.09
glass
3 40 to 700 Ni/iron 8.1 15.6 ± 0.05 ± 0.001 0.09
4 150 to 5,000 Ni/iron 8.1 15.2 ± 0.1 ± 0.001 0.7
5 1,500 to 50,000 Ni/iron 8.1 14.0 ± 0.5 ± 0.001 7
6 Above 7,500 Ni/iron 8.1 11.0 ± 1 ± 0.002 35
I.4 Description of the Equipment
Refer to Figures 1 through 4. Specic items identied on the Falling Ball Viscometer are identied by
parentheses ( ) in the following steps:
1. The Falling Ball Viscometer
must be level. The level is adjusted using the two Leveling
Screws (4) on the base. Adjust so that the bubble level on top of the Falling Ball Viscometer
is centered within the circle. Check level periodically during use.
2. a. The working angles of the KF20 are 80°, 70°, 60° and 50° relative to horizontal. The
DIN 53015 working position of 80° is the preferred position. The different working
angles are secured by a locking adjustment screw (5). To select a working angle, the
adjustment screw (5) should be loosened by turning it counter-clockwise approximately
one rotation. After the working angle is selected, the adjustment screw should then be
tightened again.
b. The working angle of the KF10 Viscometer is xed at the DIN 53015 position of 80°
relative to horizontal.
3. The two running directions of the balls can be chosen by swivelling the viscometer, which
is mounted in the stand, and is secured by a locking mechanism (14).
4. The sample tube (6) is surrounded by a water jacket which is xed between the upper plate
(7) and lower plate (8). The upper locking plug (16) with lid (20), the lower locking plug
(17) and accompanying seals (gaskets and washers) (19), and the caps (18) are designed to
perform the following functions within the sample tube:
a. keep the liquid sample tightly sealed
Brookeld Engineering Labs., Inc. Page 5 Manual No. M09-352-B0411
b. eliminate the formation of air bubbles
Ball Gauge (p/n FB68)
Balls (set of 6)
(p/n FB1-FB6)
Case (p/n FB22)
c. avoid a build up of pressure (see Fig. 3 and 4)
5. Mounted on the lower plate are tubes (10) to which the circulating temperature bath tubing
is attached.
NOTE: Any alteration, modication or replacement of the sample tube, water jacket,
falling tube screw ttings, tension rods or balls renders the ball constants invalid
and requires the re-calibration of the viscometer. See Appendix B.
6. The thermometer fastening screw (11) and sealing washer (13) with inserted thermometer
is screwed into the screw neck (12) in the upper plate. The thermometer fastening screw
should be tightened securely to prevent uid leakage.
7. The primary function of the ball gauge is to distinguish the two glass balls (Ball No. 1 and
Ball No. 2) from each other. Ball No. 1 will not pass through the ball gauge, whereas Ball
No. 2 will pass through. The ball gauge may also be used to help identify Ball No. 2 through
4.
Figure 1
NOTES:
Ball diameters, weights, densities and ball constants (forwards and backwards) are
listed in the test certicate accompanying the viscometer.
Brookeld Engineering Labs., Inc. Page 6 Manual No. M09-352-B0411
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