Overview of Cannon Viscometers

  • Manufactured by: Cannon Instruments


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Product Description:

Glass Capillary Viscometers
Why does CANNON offer so many different types of glass capillary viscometers? Primarily because no single capillary viscometer is ideally suited for all kinematic viscosity determinations. Individual analysts also have their own preferences. The brief descriptions on the following page may assist you in determining which viscometer is most appropriate for your particular application.

Expanded Uncertainty
Instead of listing the precision of our glass capillary viscometers, we now provide the expanded uncertainty. This is the universally accepted statistic when dealing with calibration data. In order to maintain A2LA accreditation, we are required to determine and specify the expanded uncertainty for all our calibration data.
ISO publications define expanded uncertainty as "quantity defining the interval about the result of a measurement within which the values that could reasonably be attributed to the measurement may be expected to lie with a high level of confidence."
Our use of expanded uncertainty instead of precision does not reflect any change in the accuracy or quality of our viscometers. It is a statistical term that is more comprehensive than precision. When comparing the accuracy of viscometers it is essential that the expanded uncertainty be specified.
A certificate specifying the expanded uncertainty is provided with every calibrated viscometer. We also provide such a certificate with every bottle of viscosity standard.

Cannon-Fenske Routine
The Cannon-Fenske Routine viscometer is a rugged and inexpensive viscometer that works well if the liquid to be measured is transparent or translucent. In general, if the meniscus (the curvature at the top of the liquid column) can be readily observed through a column of liquid 3-mm in diameter, the Cannon-Fenske Routine viscometer and other transparent-type viscometers (such as the Zeitfuchs Transparent and BS/U-Tube viscometers) can be used.

Cannon-Fenske, Cannon-Ubbelohde, and Cannon-Ubbelohde Dilution Viscometers

Size
Approx. constant cSt/s
Range centistokes*
25
0.002
0.5 to 2
50
0.004
0.8 to 4
75
0.008
1.6 to 8
100
0.015
3 to 15
150
0.035
7 to 35
200
0.1
20 to 100
300
0.25
50 to 250
350
0.5
100 to 500
400
1.2
240 to 1200
450
2.5
500 to 2500
500
8
1600 to 8000
600
20
4000 to 20 000
650
45
9000 to 45 000
700
100
20 000 to 100 000

* Ranges in centistokes represent flow times of 250 to 1000 seconds for Size 25, and 200 to 1000 for all other sizes.

Ubbelohde

The Ubbelohde viscometer and other suspended level viscometers are also used to measure transparent liquids. Unlike the Cannon-Fenske Routine viscometer, suspended level viscometers possess the same viscometer constant at all temperatures. This property is advantageous when measurements are to be made at a number of different temperatures. CANNON has improved the design of the Ubbelohde viscometer to make a more rugged instrument called the Cannon-Ubbelohde viscometer. Other suspended level viscometers in this catalog include the BS/IP/SL, BS/IP/SL(S), and BS/IP/MSL viscometers.

Size
Approx. constant cSt/s
Range centistokes*
0
0.001
0.3 to 1
0C
0.003
0.6 to 3
0B
0.005
1 to 5
1
0.01
2 to 10
1C
0.03
6 to 30
1B
0.05
10 to 50
2
0.1
20 to 100
2C
0.3
60 to 300
2B
0.5
100 to 500
3
1.0
200 to 1000
3C
3.0
600 to 3000
3B
5.0
1000 to 5000
4
10
2000 to 10 000
4C
30
6000 to 30 000
4B
50
10 000 to 50 000
5
100
20 000 to 100 000

* Ranges in centistokes represent flow times of 300 to 1000 seconds for Size 0, and 200 to 1000 seconds for all other sizes.

Reverse Flow Viscometers

Special reverse flow viscometers have been designed for testing opaque liquids. Reverse flow viscometers wet the timing section of the viscometer capillary only during the actual measurement. The Cannon-Fenske Opaque, Zeitfuchs Cross-Arm, and BS/IP/RF U-Tube viscometers are all reverse flow types. Reverse flow viscometers must be cleaned, dried, and refilled before a repeat measurement can be made. By contrast, other viscometer types commonly used to measure transparent liquids allow the same sample to be repeatedly drawn up into the capillary, permitting multiple measurements for verification.

Small Volume Viscometers

In some situations, such as in a clinical laboratory, the amount of liquid available for measurement is quite small. Several viscometers have been designed which require one milliliter or less of liquid. These are referred to as semi-micro or micro viscometers. The Cannon-Manning Semi-Micro is a U-tube viscometer that has been modified to measure the kinematic viscosity of samples as small as 1.0 mL. The Cannon-Ubbelohde Semi-Micro viscometer is a modification of the standard size Cannon-Ubbelohde viscometer requiring a sample volume of only one milliliter.
The Cannon-Manning Semi-Micro Extra Low Change viscometer will permit kinematic viscosity determination with as little as 0.5 milliliters of sample.

Dilution Viscometers

Estimates of the molecular size and shape of large polymer molecules can be obtained from kinematic viscosity measurements of dilute solutions of the polymers. The Cannon-Ubbelohde Dilution viscometer has an extra-large reservoir which allows polymer solutions to be diluted several times. Dilute polymer solutions frequently appear to exhibit changes in kinematic viscosity when the shear rate is changed. By using the Cannon-Ubbelohde Four-Bulb Shear Dilution viscometer, measurements can be made at four different shear rates.

Vacuum Viscometers

In most glass capillary viscometers, the samples flow under gravity. When liquids are too viscous to flow readily under gravity, vacuum viscometers may be used to measure viscosity (in mPa•s or cP). In these instruments a vacuum is applied to one end of the viscometer to pull the liquid through the capillary into the timing bulb(s). CANNON offers several types of vacuum viscometers, including the Cannon-Manning Vacuum, the Asphalt Institute Vacuum, and the Modified Koppers Vacuum. Like the Cannon-Fenske Opaque viscometer, these are all “reverse flow” viscometers. Vacuum viscometers require a vacuum that is very accurately controlled. The CANNON DVR-1000 or DVR-1500 Digital Vacuum Regulator is an ideal instrument for maintaining constant vacuum.