This is an update of an article originally published in December 2013 - Three years ago.
Automatic surface tension tensiometers have capabilities to die for. For example they are one button operations, can track changes in surface tension over time, give indications of contact contact angle and much more.
However, Automatic tensiometers are expensive - three to four times more than a high-precision manual tensiometer. We hope to clearly depict when an automatic digital tensiometer is not merely nice to have, but essential.
The duNouy Ring method is based on a technique developed by P. Lecomite duNouy and popularized in a paper published in 1925. In this technique a platinum ring is first submerged below the surface of a liquid
The duNouy method has been used for measuring a wide range of products. It can be used for very low surface tensions, and any surface tension up to a high of 90 dynes/cm. Traditional torsion balance tensiometers are still in wide use because of their inherent precision and stability.
The Wilhelmy plate method is based
If your requirements call for measuring only surface tension, the more basic duNouy ring tensiometer is probably the best choice. When you have very thick, high viscosity requirements a Wilhelmy Plate instrument will work.
When conducting basic surface tension tests, in normal ranges, we recommend the duNouy Ring Tensiometer. if you also need Wilhelmy Plate tests we can recommend something like the CSC Digital Tensiometer which can process both duNouy and Wilhelmy plate methods.
If you have requirements for measuring surface tension which change over time, such as measuring the reaction times of surfactant, the Automatic Tensiometer is a good solution.
An automatic tensiometer has unique capabilities for determining Lamella Length,
Measurements of changes in apparent surface tension or wettability of different substrates are enhanced with automated techniques.
Most automatic tensiometers have attachments that will control the temperature of the sample.
Most automatic tensiometers also perform routine duNouy Ring and Wilhelmy plate tests. These instruments also record historical results, perform statistical analyses of multiple tests, and plot test readings.
A number of testing requirements clearly point to the need for an automatic tensiometer.
If these are part of your analysis requirements, an automatic Tensiometer is the practical answer. The ability to conduct your
We hope this has provided some guidance for the answer to When Do I Need An Automatic Tensiometer?
If you found this useful please share it with you colleagues who work with surface tension.
The wide range of issues involved with selection and use of laboratory test equipment frequently baffle but always interest me.
Hope we help.
Art
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