Brookfield Dial Viscometer User Manual

BROOKFIELD DIAL VISCOMETER

Operating Instructions

Manual No. M/85-150-P700

Please record the Model and Serial Number of your viscometer.
Having this information readily available will help us to assist you
should there be any questions regarding your instrument.

Model No. _____________________

Serial No. _____________________

SPECIALISTS IN THE
MEASUREMENT AND
CONTROL OF VISCOSITY

BROOKFIELD ENGINEERING LABORATORIES, INC.

11 Commerce Boulevard, Middleboro, MA 02346-1031 USA
T

EL

508-946-6200 or 800-628-8139 FAX [phone]

www.brookfieldengineering.com

Brookfield Engineering Laboratories, Inc. Page 1 Manual No. M/85-150-P700

TABLE OF CONTENTS

I. INTRODUCTION................................................................................3

I.1 Components .................................................................................... 3

I.2 Utilities ........................................................................................... 4

I.3 Specifications ................................................................................. 4

I.4 Set-Up............................................................................................. 4

II. GETTING STARTED..........................................................................5

II.1 Operation ........................................................................................ 5

II.2 Viscometer Readings and Viscosity Calculations.......................... 5

II.3 Considerations for Making Measurements..................................... 8

APPENDIX A - Cone/Plate Viscometer Set-Up........................................ 9

APPENDIX B - Viscosity Ranges ...........................................................18

APPENDIX C - Variables in Viscosity Measurements............................20

APPENDIX D - Calibration Procedures .................................................. 22

APPENDIX E - Models A & A-E Laboratory Stands

with Parts Identification ........................................... 29

APPENDIX F - Fault Diagnosis and Troubleshooting ........................... 31

APPENDIX G - Warranty Repair and Service ........................................ 33

Tear-off Sheet - Viscosity Test Report ....................................................35

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I. INTRODUCTION

The Brookfield Dial Viscometer measures fluid viscosity at given shear rates. Viscosity is a measure
of a fluid’s resistance to flow. You will find a detailed description of the mathematics of viscosity
in the Brookfield publication “More Solutions to Sticky Problems” a copy of which was included
with your Dial Viscometer. The Dial Viscometer rotates a sensing element in a fluid and measures
the torque necessary to overcome the viscous resistance to the induced movement. This is
accomplished by driving the immersed element, which is called a spindle, through a beryllium copper
spring. The degree to which the spring is wound, indicated by the red pointer, is proportional to the
viscosity of the fluid.

The Viscometer is able to measure over a number of ranges since, for a given spring deflection, the
actual viscosity is proportional to the spindle speed and is related to the spindle's size and shape. For
a material of given viscosity, the resistance will be greater as the spindle size and/or rotational speed
increase. The minimum viscosity range is obtained by using the largest spindle at the highest speed;
the maximum range by using the smallest spindle at the slowest speed.

There are four basic spring torque series offered by Brookfield:

Model Spring Torque (Dyne-cm)

LV 673.7

RV 7,187.0
HA 14,374.0
HB 57,496.0

The higher the torque calibration, the higher the measurement range. The viscosity measurement
range for each torque calibration may be found in Appendix B.

All units of measurement are calculated in units of centipoise (cP) by using a look-up table
known as "the Brookfield Factor Finder" to convert torque reading. The equivalent units of

measurement in the SI system are calculated using the following conversions:

CGS SI

Viscosity: 1 cP = 1 mPa•s mPa•s = milli Pascal - second
Torque: 107 dyne-cm = 1 Newton-m

I.1Components

1) Dial Viscometer

2) Model A Laboratory Stand

3) Spindle Set with Case (4 spindles for LVF, LVT; 7 Spindles for RVF, RVT, HAT, and HBT).
For Cone/Plate versions: a spindle wrench, one cone spindle and a sample cup (Part No.
CP-44Y) replace the spindle set

4) Guard Leg (LVF, LVT, RVF, and RVT only)

5) Carrying Case

6) Operating Instruction Manual

7) Factor Finder

Please check to be sure that you have received all components, and that there is no damage. If you
are missing any parts, please notify Brookfield Engineering or your local Brookfield agent immedi­ately. Any shipping damage must be reported to the carrier.

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I.2 Utilities

Input Voltage: 115 VAC or 230 VAC
Input Frequency: 50 or 60 Hz
Power Consumption: Less than 20 WATTS

I.3 Specifications

Speeds: LVF: 60, 30, 12, 6

LVT: 60, 30, 12, 6, 3, 1.5, 0.6, 0.3
RVF: 20, 10, 4, 2

RVT: 100, 50, 20, 10, 5, 2.5, 1, 0.5
HAT: 100, 50, 20, 10, 5, 2.5, 1, 0.5

HBT: 100, 50, 20, 10, 5, 2.5, 1, 0.5

Accuracy: ± 1% of Full Scale Range in use

(See Appendix D for details)

Repeatability: ± 0.2% of Full Scale Range in use

Weight: Gross Weight 20 lb 9 kg

Net Weight 17 lb 7.7 kg
Carton Volume 1.65 cu ft 0.05 m

3

Operating
Temperature: -20°C (-4°F) to 65°C (149°F)

I.4 Set-Up

1) Assemble the laboratory stand. (Refer to Appendix E.)

2) Mount the Viscometer securely on a Brookfield laboratory stand. On some Viscom­eters, it may be necessary to unscrew the nut located at the point where the power cord
enters the viscometer. This permits the metal handle to be inserted into the laboratory
stand clamp.

Note: The position of the laboratory stand clamp assembly is important. Refer to

Appendix E for proper alignment and positioning of the clamp assembly.

Level the viscometer, referring to the bubble level on the instrument. If the
viscometer cannot be leveled, recheck the laboratory stand assembly, as shown on
Sheet #82-0330 (supplied with Model A laboratory stand).

3) Verify that the viscometer's power requirements match your power source before
connecting it to power.

4) For Cone/Plate models, refer to Appendix A.

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II.GETTING STARTED

II.1 Operation

The Brookfield Viscometer is powered by a precision synchronous motor. Exact speeds of rotation
are assured as the motor will turn erratically and spasmodically if synchronization cannot be
maintained.

Speed changes are affected by a gear train having either four or eight speeds. Maximum speed
(RPM) will be set at full clockwise rotation and minimum speed at full counter-clockwise rotation.
Although not absolutely necessary, it is advisable to change speeds while the motor is running.

Four speed Viscometers have a square speed control knob with one number shown on each of four
faces. The instrument’s rotational speed is indicated by the number facing up. Eight speed models
have a square speed control knob with two numbers on each face; by moving the knob through two
complete turns, speeds may be changed in sequence. No trouble will be experienced in differenti­ating between the two speeds shown on each face since each pair is in the ratio of 20:1. To insure
rotation at the indicated speed, it is important that the face of the knob upon which this speed is shown
be closely parallel to the viscometer’s dial.

LV Viscometers are provided with a set of four spindles and a narrow guard leg; RV Viscometers
come with a set of seven spindles and a wider guard leg; HA and HB Viscometers come with a set
of seven spindles and no guard leg.

The spindles are attached to the viscometer by screwing them to the lower shaft. Note that the
spindles have a left-hand thread. The lower shaft should be held in one hand and lifted up. The
spindle should be screwed to the left. The face of the spindle nut and the matching surface on the
lower shaft should be smooth and clean to prevent eccentric rotation of the spindle. Spindles can
be identified by the number on the side of the spindle nut.

All Brookfield Dial Reading Viscometers are provided with a clutch lever located at the back of the
instrument. Depressing the lever raises the dial against the pointer and “holds” the instrument’s
reading. When the clutch is released the dial is lowered and the pointer will be freed.

Any of the controls on the Viscometer - the motor switch, speed change knob, and clutch - may be
operated independently of the other.

II.2 Viscometer Readings and Viscosity Calculations

1. Mount the guard leg, if used, (spindle protector) on the viscometer.

2. Attach the spindle (left-hand thread) to the viscometer lower shaft by lifting the coupling screw
slightly. Hold it firmly with one hand while screwing the spindle on with the other (note left-hand
thread). Avoid putting side thrust on the shaft.

To avoid trapping air bubbles under the disc-type spindles, do the following before attaching the
spindle. Begin by immersing the spindle in a diagonal path, slowly drag the spindle across the

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fluid surface, and bring the spindle to an upright position and thread onto screw.

3. Lower and center spindle in the test material (600 ml beaker) until the "meniscus" of the fluid is
at the center of the immersion groove on the spindle’s shaft.

4. To make a viscosity measurement, turn the motor switch “ON”. This energizes the viscometer
drive motor. Allow time for the indicated reading to stabilize. The time required for stabilization
will depend on the speed at which the viscometer is running and the characteristics of the sample
fluid.

When making a viscosity measurement, the reading should be noted and multiplied by the factor
appropriate to the viscometer model/spindle/speed combination being used. Refer to the table
below or to the FACTOR FINDER for calculating viscosity. For maximum accuracy, readings
below 10.0% torque (dial reading) should be avoided.

5. Turn the viscometer motor switch “OFF” when changing a spindle, changing samples, etc.
Remove spindle before cleaning.

6. The interpretation of results and the instrument’s use with non-Newtonian and thixotropic
materials is discussed in the booklet, “More Solutions to Sticky Problems” and in Appendix C.

The following tables apply to Brookfield Viscometer Models LV, RV, HA and HB with standard
spindles. They enable the user to convert the percent scale reading into a viscosity value in units of
centipoise.

To convert the viscometer dial reading to a viscosity value in units of centipoise, multiply the reading
noted on dial viscometer by the appropriate factor in the following tables.

LV Series Viscometer

1234

.3 200 .3 1K.3 4K.3 20

.6 100 .6 500 .6 2K.6 10

1.5 40 1.5 200 1.5 800 1.5 4

3 20 3 100 3 400 3 2

6 10 6 50 6 200 6 1

12 5 12 25 12 100 12 500

30 2 30 10 30 40 30 200

60 1 60 5 60 20 60 100

= Spindle
= Factor

= Spindle Speed

K = 1000

K

K
K
K
K

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RV Series Viscometer

1234567

.5 200 .5 800 .5 2K.5 4K.5 8K.5 20K.5 80

1 100 1 400 1 1K12K14K110K140
2 50 2 200 2 500 2 1K22K25K220

2.5 40 2.5 160 2.5 400 2.5 800 2.5 1.6K2.5 4K2.5 16
4 25 4 100 4 250 4 500 4 1K4 2.5K410
5 20 5 80 5 200 5 400 5 800 5 2K58

10 10 10 40 10 100 10 200 10 400 10 1K10 4
20 5 20 20 20 50 20 100 20 200 20 500 20 2
50 2 50 8 50 20 50 40 50 80 50 200 50 800

100 1 100 4 100 10 100 20 100 40 100 100 100 400

= Spindle

= Spindle Speed

= Factor

K = 1000

HA Series Viscometer

1234567

.5 400 .5 1.6K.5 4K.5 8K.5 16K.5 40K.5 160

1 200 1 800 1 2K14K18K120K180
2 100 2 400 2 1K22K24K210K240

2.5 80 2.5 320 2.5 800 2.5 1.6K2.5 3.2K2.5 8K2.5 32
5 40 5 160 5 400 5 800 5 1.6K54K516

10 20 10 80 10 200 10 400 10 800 10 2K10 8
20 10 20 40 20 100 20 200 20 400 20 1K20 4
50 4 50 16 50 40 50 80 50 160 50 400 50 1.6

100 2 100 8 100 20 100 40 100 80 100 200 100 800

K
K

K
K
K
K

K
K
K
K

K
K
K
K
K

K

= Spindle

= Spindle Speed

= Factor

K = 1000

HB Series Viscometer

1234 567

.5 1.6K.5 6.4K.5 16K.5 32K.5 64K.5 160K.5 640

1 800 1 3.2K18K116K132K180K1 320
2 400 2 1.6K24K28K216K240K2 160

2.5 320 2.5 1.28K2.5 3.2K2.5 6.4K2.5 12.8K2.5 32K2.5 128
5 160 5 640 5 1.6K5 3.2K5 6.4K516K564

10 80 10 320 10 800 10 1.63K10 3.2K10 8K10 32
20 40 20 160 20 400 20 800 20 1.6K20 4K20 16
50 16 50 64 50 160 50 320 50 640 50 1.6K50 6.4

100 8 100 32 100 80 100 160 100 320 100 800 100 3.2

= Spindle

= Spindle Speed

= Factor

K = 1000

K
K
K

K
K
K
K

K
K

Dial reading x Factor = Viscosity in cP (mPa•s)

Example: LVT Viscometer with #1 spindle at 6 rpm

Dial Reading: 75 Factor: 10

75 x 10 = 750 cP (mPa•s)

Full scale viscosity range for any speed and spindle combination is equal to the factor x 100.

Factor x 100 = Full scale range

Example: LVT Viscometer with #1 spindle at 6 RPM

Full Scale Range: 10 x 100 = 1,000 cP

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II.3Considerations for Making Measurements

In taking viscosity measurements with the Dial Viscometer there are two considerations which
pertain to the low viscosity limit of effective measurement.

1) Viscosity measurements should be accepted within the equivalent % Torque Range from
10% to 100% for any combination of spindle/speed rotation.

2) Viscosity measurements should be taken under laminar flow conditions, not under turbulent
flow conditions.

The first consideration has to do with the precision of the instrument. All Dial Viscometers have a
full scale range precision of ± 1% for any spindle/speed combination. We discourage taking readings
below 10% of range because the potential viscosity error of ± 1% is a relatively high number
compared to the instrument reading.

The second consideration involves the mechanics of fluid flow. All rheological measurements of
fluid flow properties should be made under laminar flow conditions. Laminar flow is flow wherein
all particle movement is in layers directed by the shearing force. For rotational systems, this means
all fluid movement must be circumferential. When the inertial forces on the fluid become too great,
the fluid can break into turbulent flow wherein the movement of fluid particles becomes random and
the flow can not be analyzed with standard math models. This turbulence creates a falsely high
viscometer reading with the degree of non-linear increase in reading being directly related to the
degree of turbulence in the fluid.

For the following geometries, we have found that an approximate transition point to turbulent flow
occurs as follows:

1) No. 1 LV Spindle: 15 cP at 60 RPM

2) No. 1 RV Spindle: 100 cP at 50 RPM

3) UL Adapter: 0.85 cP at 60 RPM

Turbulent conditions will exist in these situations whenever the RPM/cP ratio exceeds the values
listed above.

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APPENDIX A - Cone/Plate Viscometer Set-Up

The Wells-Brookfield Dial Viscometer uses the same operating instruction procedures as described in
this manual, however, the gap between the cone and the plate must be mechanically adjusted before
measurements are made. This is done by moving the plate (built into the sample cup, Part No. CP-44Y)
up towards the cone until two small pins (one in the cone, the second mounted on the plate) contact
slightly, and then by separating (lowering) the plate 0.0005inch (0.013mm).

Note that the Wells-BrookfieldCone/Plate Viscometer requires the use of a circulating temperature bath
controlling temperature to within +/- 0.1 °C. The bath is connected to the ports on the CP-44Y sample
cup. Brookfield offers a complete line of refrigerated and non-refrigerated (tap water cooling)
circulating water baths.

The following example assumes that the C/P Viscometer is set up on the Model A laboratory stand and
has been leveled. Cone CP-40 is used in the illustrations. The water bath is on, set at the same test
temperature that you will use when measuring the viscosity of your sample and is connected to the sample
cup (Figure A1). Allow enough time for the bath to reach the test temperature. The Viscometer speed
knob should be set at 10 or 12 rpm with motor OFF.

Bath

Outlet

PUMP

OUTLET

Water

Bath

PUMP
INLET

Cup

Outlet

Bath
Inlet

Figure A1

Adjustment

Cup
Inlet

Ring

Sample

Cup

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Remove the sample cup and attach the cone to the Viscometer (Note: left hand threads), using the spindle
wrench to hold the Viscometer shaft (Figure A2). Note: Lift up gently on the spindle wrench.

These surfaes

must be clean!

Spindle Wrench

Cone

Figure A2

Attach the sample cup and swing the clip under the cup to secure it in place. Take care to avoid hitting
the cone with the cup (Figure A3). Note: Do not add test sample during the gap setting procedure.

Do Not Hit

the CONE

with the CUP!

Figure A3

Start the Viscometer running at 10 or 12 rpm. Readings of % Torque (dial reading) will be utilized for
setting the cone/plate gap. If the display reading jumps to 0.5% of scale (or higher), or will not settle to
zero (indicating that the pins on the cone and cup are hitting), unscrew the adjustment ring by turning
it to the left (clockwise as you look down on the instrument) until the reading settles at 0.0% (Figure A4).

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Index Mark

Adjustment Ring

Turn Adjusting Ring clockwise until

the % torque display is stable at 0.0%

Figure A4

Turn the adjustment ring to the right (counterclockwise as you look down on the instrument) in small
increments (one or two divisions of the ring) while watching the Viscometer dial (Figure A5).
Remember that you are trying to raise the cup so that the pin in the cone touches the pin in the cup. Once
you have found this hit point, you can "back off" to create the desired gap between cone and cup. You

must wait at least 6 seconds between movements of the ring.

Turn the adjustment ring until the display reading jumps from 0.0 to 0.5% (HA and HB models) or from

0.0 to 0.5 % (RV models) or 0.0 to 1.0% (LV models). This is the HIT POINT. The cup may have to
be adjusted up and down several times before this deflection is satisfactorily reached. The LV series
Viscometer will be the most sensitive.

Index Mark

Adjustment Ring

Turn Adjustment Ring Counter-

clockwise in Small Increments

Figure A5

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