Product category:
Viscometers and rheometers
News Release from: Labtex | Subject: Cannon viscometers
Edited by the Laboratorytalk Editorial
Team on 28 March 2006
Cannon glass capillary viscometers from
Labtex
A wide variety of glass capillary tubes, including Cannon-Fenske Routine, Ubbelohde, and Cannon-Fenske Opaque, Zeitfuchs Cross-Arm, and BS/IP/RF U-Tube viscometers is available
A wide variety of glass capillary tubes is available for kinematic viscosity measurements Cannon viscometer tubes are designed for numerous applications
This article was originally published on Laboratorytalk on 30 Sep 2005 at 8.00am (UK)
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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 3mm 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.
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Flash point testers from the original Mr Pensky
Fully automatic Pensky Martens flash point tester is pre-programmed with 14 standard test methods and user definable search programs for the examination of oils, fuels, lubricants and bitumens
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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.
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 1.0ml.
The Cannon-Ubbelohde Semi-Micro viscometer viscometer requiring a sample volume of only one millilitre.
The Cannon-Manning Semi-Micro Extra Low Change viscometer will permit kinematic viscosity determination with as little as 0.5milliliters 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 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.
A certificate specifying the expanded uncertainty is provided with every calibrated viscometer.
Expanded uncertainty.
Instead of listing the precision of our glass capillary viscometers, Cannon now provide the expanded uncertainty, the universally accepted statistic when dealing with calibration data.
In order to maintain A2LA accreditation, Cannon is required to determine and specify the expanded uncertainty for all 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'.
Cannon also provide such a certificate with every bottle of viscosity standard reference oil. Request a free brochure from Labtex ...
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