Brookfield KF40 Operating Instructions Manual

BROOKFIELD KF40

Falling Ball Viscometer

Operating Instructions

Manual No. M19-354

INSTRUMENTATION & SPECIALTY CONTROLS DIVISION

11 Commerce Boulevard, Middleboro, MA 02302 USA

Tel: [phone] or 800-628-8139 (USA excluding MA)
Fax: [phone] Internet http://www.brookfieldengineering.com

Table of Contents

I. INTRODUCTION ..................................................................................................5

I.1 Components....................................................................................................................................................5

I.2 Specications ..................................................................................................................................................6

I.3 Details on Viscosity Measurement Range ............................................................................................7

I.4 Description of the Equipment ..................................................................................................................7

I.5 Safety Symbols and Precautions ...........................................................................................................10

I.6 Cleaning ......................................................................................................................................................... 10

II. GETTING STARTED ............................................................................................11

II.1 Choice of Balls .............................................................................................................................................. 11

II.2 Filling the Sample Tube ............................................................................................................................ 11

II.3 Temperature Control of the Sample .................................................................................................... 12

II.4 Measuring the Falling Time.....................................................................................................................12

III. CALCULATIONS .................................................................................................14

III.1 Dynamic Viscosity ...................................................................................................................................... 14

III.2 Kinematic Viscosity .................................................................................................................................... 15

IV. DETERMINATION OF THE NON-NEWTONIAN BEHAVIOR ............................... 16

IV.1 ixotrophy/Rheopexy ................................................................................................................... 16

IV.2 Structural Viscosity (Pseudoplasticity and Dilatancy) ............................................................... 16

Appendix A - Maintenance ..................................................................................................17

Appendix B - Calibration of the Ball Constants ................................................................18

Appendix C - Online Help and Additional Resources ......................................................19

Appendix D - Warranty Repair and Service .......................................................................20

I. INTRODUCTION

Falling Ball Viscometer, Model KF40, complies 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 KF40
are variable at 80°, 70°, 60° and 50° relative to horizontal. The water jacket, surrounding the
falling tube, when connected to a Brookeld 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 dierence 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

certicate accompanying the instrument. You must provide the density value for the
liquid that you are testing.

The six (6) balls with dierent diameters and densities enable the KF40 to measure a wide

range of viscosities. The ability to adjust the angle of inclination extends the measuring range

for low viscosity liquids.

For non-Newtonian liquids, by subjecting the same sample to repetitive measurements with the
KF40 at dierent angles, pseudoplastic or dilatant behavior may be determined as explained in
Section IV. Time dependent behavior (thixotropy and rheopexy) may also be noted.

The ease of operation and precise temperature control, using a Brookeld circulating temperature

bath, allows for very reproducible measuring results.

I.1 Components

Component Part No. Quantity

KF40 Falling Ball Viscometer KF40 1

Set of (6) balls with gauge (FB68) in a carrying case (FB26) FB30C 1
Supplied w/certicate 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

Wire Cleaning Brush for Sample Tube FB53 1
Brush to clean loose debris from Falling Balls FB52 1

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©2019 AMETEK Brookfield Inc. All rights reserved.

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 M11-353 1

Instrument Case FB200 1

Latex rubber tubing, 5/16 I.D. x 1/16 wall FB69 1

Certicate of Calibration ____ 1

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: 15.94 mm +/- 0.01 mm

Set of Balls: 6 balls

Working Angle: KF40: 80°, 70°, 60°, 50°

Temperature Range: -5°C - +150°C

Sample Volume: 40 mL

Viscometer Accuracy: ±0.6% if the reading when used with balls 2 and 3.

Dimensions: 180 mm x 220 mm x 330 mm

Weight: 6.4 lbs, 2.9 kg
(empty glass tube and empty waterbath jacket)

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©2019 AMETEK Brookfield Inc. All rights reserved.

M19-354