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Wells-Brookfield
Cone/Plate
Rapid
Determination Of Absolute Viscosity
Introduction
The Wells-Brookfield Cone/Plate Viscometer gives researchers a
sophisticated instrument for routinely determining absolute
viscosity of fluids in small sample volumes. Its cone and plate
geometry provides the precision necessary for development of
complete rheological data.
Principle
of Operation
The Wells-Brookfield Cone/Plate Viscometer is a precise torque
meter which is driven at discrete rotational speeds. The torque
measuring system, which consists of a calibrated
beryllium-copper spring connecting the drive mechanism to a
rotating cone, senses the resistance to rotation caused by the
presence of sample fluid between the cone and a stationary flat
plate.
The
resistance to the rotation of the cone produces a torque that is
proportional to the shear stress in the fluid. The amount of
torque is indicated either on a dial or digital display,
depending on model. This reading is easily converted to absolute
centipoise units (mPa·s)
from pre-calculated range charts. Alternatively, viscosity can
be calculated from the known geometric constants of the cone,
the rate of rotation, and the stress related torque. See
Range Tables
The
correct relative position of cone and plate is obtained by
following a simple mechanical procedure without the need for
external gauges or supplementary instrumentation.
The
stationary plate forms the bottom of a sample cup which can be
removed, filled with .5 ml to 2.0 ml of sample fluid (depending
on cone in use), and remounted without disturbing the
calibration. The sample cup is jacketed and has tube fittings
for connection to a constant temperature circulating bath.
The
system is accurate to within ?.0% of the working range.
Reproducibility is to within ?.2%. Working temperature range is
from 0oC to 100oC.
Various
cone spindles are available for use with the Wells-Brookfield
Cone/Plate instruments. One cone spindle is provided with the
instrument and is calibrated for use with the sample cup.
Additional cone spindles may be purchased and will be calibrated
for use with the same sample cup.
Versatility
of Application
- The
Wells-Brookfield Cone/Plate Viscometer provides a wide
variety of shear rates and viscosity ranges, which can be
further extended by the use of interchangeable cone
spindles. Different models can be selected to meet the
specific range of viscosities and shear rates required.
(Range Table)
- Shear
rates as high as 1875 sec-1 (DV-III Rheometer) can be
achieved.
- The
small sample volume required permits rheological evaluations
to be made on materials where sample availability is
limited, such as biological fluids and thick film coatings
that contain precious metals.
- All
wetted parts are stainless steel for corrosion resistance
and ease of cleaning.
- Optional
purge fitting, luer fitting, and embedded temperature probe
available.
Electronic
Gap Setting
Wells-Brookfield Cone/Plate Digital Viscometers/Rheometers are
now supplied with an advanced "Electronic Gap Setting"
feature. This technology allows faster set-up time and minimizes
the possibility of "gap" adjustment errors. With the
enhanced system, a bright LED lights up when a "hit
point" is achieved. A simple turn of the micrometer
adjustment ring and the "gap" is set, reducing the
time required associated with manual detection methods.
The new electronic gap setting system is now a standard feature
on our complete line of Wells-Brookfield Cone/Plate Digital
Viscometers/Rheometers. These instruments provide precise shear
profiles necessary to determine viscosity and develop
rheological data.
LV
SERIES VISCOMETERS & RHEOMETERS
Cone
Spindle*
|
LVT
|
LVDV-I+
|
LVDV-II+*
|
LVDV-III
|
Shear
Rate** (sec-1)
|
Sample
Volume (mL)
|
CPE-40
CPE-41
CPE-42
CPE-51
CPE-52
|
CP-40
CP-41
CP-42
CP-51
CP-52
|
0.5-1,023
1.9-3,837
1.0-2,000
8.0-16,000
15.4-30,720
|
0.3-1,023
1.2-3,837
0.6-2,000
4.9-16,000
9.3-30,720
|
0.2-3,070
0.6-11,150
0.3-6,000
2.4-48,000
4.6-92,160
|
0.1-3,070
0.5-11,150
0.2-6,000
1.9-48,000
3.7-92,160
|
7.50N
2.00N
3.84N
3.84N
2.00
|
0.5
2.0
1.0
0.5
0.5
|
RV
SERIES VISCOMETERS & RHEOMETERS
¡¡
Cone
Spindle*
|
RVT
|
RVDV-I+
|
RVDV-II+**
|
RVDV-III
|
Shear
Rate*** (sec-1
|
Sample
Volume (ml)
|
CPE-40
CPE-41
CPE-42
CPE-51
CPE-52
|
CP-40
CP-41
CP-42
CP-51
CP-52
|
3.3-6,450
12.3-24,560
6.4-12,800
51.2-102,400
98.3-30,720
|
3.3-10,900
12.3-40,933
6.4-21,300
51.2-170,666
98.3-327,666
|
1.6-32,700
6.1-122,800
3.2-64,000
25.6-512,000
49.2-983,000
|
1.3-32,7000
4.9-122,800
2.6-64,000
20.5-512,000
39.3-983,000
|
7.50N
2.00N
3.84N
3.84N
2.00
|
0.5
2.0
1.0
0.5
0.5
|
HA
SERIES VISCOMETERS & RHEOMETERS
¡¡
Cone
Spindle*
|
HAT
|
HADV-I+
|
HADV-II+**
|
HADV-III
|
Shear
Rate***(sec-1)
|
Sample
Volume (nl)
|
CPE-40
CPE-41
CPE-42
CPE-51
CPE-52
|
CP-40
CP-41
CP-42
CP-51
CP-52
|
6.6-13,080
24.6-49,120
12.8-25,600
102.4-204,800
196.6-393,200
|
6.6-21,800
24.6-81,866
12.8-42,600
102.4-341,333
196.6-655,333
|
3.3-65,400
12.3-245,600
6.4-128,000
51.2-1,024,000
98.3-1,966,000
|
2.6-65,400
9.8-245,600
5.1-128,000
41.0-1,024,000
78.6-1,966,000
|
7.50N
2.00N
3.84N
3.84N
2.00
|
0.5
2.0
1.0
0.5
0.5
|
HB
SERIES VISCOMETERS & RHEOMETERS
¡¡
Cone
Spindle*
|
HBT
|
HBDV-I+
|
HBDV-II+**
|
HBDV-III
|
Shear
Rate*** (sec-1
|
Sample
Volume (ml)
|
CPE-40
CPE-41
CPE-42
CPE-51
CPE-52
|
CP-40
CP-41
CP-42
CP-51
CP-52
|
26.2-52,400B
98.3-196,600
51.2-102,400
409.6-819,200
786.4-1,572,860
|
26.2-87,200
98.3-327,466
51.2-170,666
409.6-1,365,333
786.4-2,621,333
|
13.1-261,600
49.1-982,400
25.6-512,000
204.8-4,096,000B 393.2-7,864,000
|
10.5-261,600
39.3-982,400
20.5-512,000
163.8-4,096,000
314.6-7,864,000
|
7.50N
2.00N
3.84N
3.84N
2.00
|
0.5
2.0
1.0
0.5
0.5
|
*CPE
refers to electronic gap adjustment, while CP-refers to manuel
gap adjustment.
**Maximum viscosity range shown is at 0.1 rpm.
***N=RPM Example: RV Viscometer with CPE-42 spindle at 10 RPM
has shear rate 3.84 x 10 = 38.4 sec-1.
CONE
SPINDLE DIMENSIONS
¡¡
CONE
SPINDLE
|
ANGLE
(deg.)
|
RADIUS
(cm)
|
CP-40
or CPE-40
|
0.8
|
2.4
|
CP-41
or CPE-41
|
3.0
|
2.4
|
CP-42
or CPE-42
|
1.565
|
2.4
|
CP-51
or CPE-51
|
1.565
|
1.2
|
CP-52
or CPE-52
|
3.0
|
1.2
|
|