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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.
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 ±1.0% of the working range.
Reproducibility is to within ±0.2%. 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
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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. 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.
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All wetted parts are stainless steel for
corrosion resistance and ease of cleaning.
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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
|
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