Automatic Tensiometer vs. Manual Tensiometer

By Hank Levi on Mon, Jan 11, 2016 @ 11:56 AM

Ever wonder what a tensiometer looked like?   

There are MANUAL TENSIOMETERS that look like this:

 manual_tensiometer-resized-600.jpg
 

PROS:

  • >Great for hands-on learning
  • >Can use virtually anywhere (does not require electricity)
  • >Easy to learn how to use
  • >Less expensive

CONS:

  • >It's manual.  You have to twist the dials by hand
  • >There is a technique to getting repeatable results
  • >Human error potential is higher
  • >Need to record results by hand

 

VIDEO DEMONSTRATION FOR MANUAL TENSIOMETER

 
 
 
 
 
 
 
 
 
 

There are AUTOMATIC TENSIOMETERS that look like this.

DY-300small.jpg
 

PROS:

  • >Easy to operate.  Press a button and walk away
  • >Run more tests quickly with high repeatability
  • >Ability to record and report data results (store historical data too)
  • >Dynamic testing features including time tests and Lamella length and more
  • >Most handle both DuNouy Ring and Wilhelmy Plate

CONS:

  • >More Expensive
  • >Some models require a computer (some don't)

VIDEO DEMONSTRATION FOR AUTOMATIC TENSIOMETER

 

To help prospective users evaluate and compare the different types of models available in the market we have prepared a reference document we call the: 

                    "Tensiometer Selection Matrix"

This matrix is not necessarily brand specific as it was designed to help those seeking to compare capabilities and prices among popular manual Tensiometer models vs. popular Automatic or "digital" Tensiometer models. 

We hope you find the Tensiometer Selection Matrix helpful in your search and evaluation of Tensiometers.

 

                        Created on 09/22/11 at 12:43:16

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How many dynes per centimeter can a tensiometer measure?

By Hank Levi on Mon, May 06, 2013 @ 11:57 AM

If your reading this post you probably already have an understanding of a few basic concepts.  For those who missed it here they are for review.

Basic Concepts

  • A dyne per centimeter is a unit of force
  • A dyne is defined as the force required to accelerate a mass of one gram at a rate of one centimeter per second squared
  • A dyne per centimeter is the unit traditionally used to measure surface tension and interfacial tension
  • Surface tension is a measurement taken on a liquid and Interfacial tension is a measurement taken between/among liquids.
  • Surface tension and Interfacial tension are both measured using an instrument called a tensiometer

I suppose it's worth mentioning why we decided to write this particular post about tensiometers and their surface tension and interfacial tension measuring limitations.   The simple explanation being that people have continued to ask us the question!  In fact, one time we had someone ask if we could recommend a tensiometer that could measure up to and above 500 dynes per centimeter! ...and we simply said "why?" and scratched our heads.

I guess you could say we finally received enough inquiries about this to force us into action and write about it.

Tensiometer readout design

If you have ever looked at a manual tensiometer guage like this one you will notice the dial only goes to 90 (90 dynes per centimeter).  

manual tensiometer

Compare this to some of the automatic tensiometers that use sensitive electronic balances and software and you will notice they have for the most part (various models) a range up to around 100 (100 dynes per centimeter).  See the red arrows below;

automatictensiometerimage

Why not make them with larger ranges?

Up to this point you have seen a couple of examples of the range capabilities for a manual and an automatic tensiometer. The truth of the matter is that the dial on the manual tensiometer could be re-etched to include additional numbers going up much higher than 90.  And the automatic tensiometers using the electronic balances could be configured and the software re-written to go as high as 1,000! 

So why haven't the engineers who make these tensiometers made the range on their tensiometers as big as they can?  Wouldn't that make the tensiometer that much more appealing?  A bigger range would mean you could measure more samples right? 

Well maybe...but not on this planet or in this universe. 

Liquids and fluidic metals?

You see, the answer is not really about the tensiometer.  In general, except for fluidic metals there are no known liquids that will indicate a surface or interfacial tension above 90/100 dynes per centimeter.  Surface tension of Mercury for example is generally reported around 480 dynes per centimeter but it does not wet to either the Wilhelmy Plate or Du Nouy Ring and cannot be measured by a traditional tensiometer.  Other fluidic metals need high temperatures and special atmoshperic conditions and are also unsuitable for traditional tensiometers.  With the exception of fluidic metals just mentioned solutions including metal ions but excluding surfactants (e.g. plating solutions) indicate comparatively high surface tension readings of 80 to 90 dynes per centimeter at most.  One of the highest surface tension liquids except Mercury is Sodium Chloride 6.0mol/20°C at 82.55 dynes per centimeter (mN/m).

In summary then, we can conclude that all of the liquids we will encounter while measuring surface tension or interfacial tension with a traditional tenstiometer will fall in the range not to exceed 100 dynes per centimeter.  Therefore restating the obvious you don't need a tensiometer that can measure surface tension above 100 dynes per centimeter.

Make sense?

 

 

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Tensiometer Ring used for ASTM D971, ASTM D1331, ASTM D1590

By Hank Levi on Fri, Nov 30, 2012 @ 11:15 AM

There are many ASTM methods companies follow.  Here are a few of the more popular ASTM methods relating to surface and interfacial tension:

  • ASTM D971; Interfacial tension of oil against water: This standard is used to evaluate hydrocarbon fluids and possible contamination levels.  Evaluating hydrocarbon fluid contamination levels is important in numerous industries including transformer oil testing and most Fuels.  Our heavy use of petroleum products and the effects of hydrocarbon fluid contamination makes for an almost limitless list of applications that require testing.
  • ASTM D1331; Solutions of surface-active agents:  This standard applies to detergents and soaps but also includes emulsifiers and surfactants.  The test method determines the surface tension of popular substances including diswasher detergents and laundrey soap mixtures in water.
    ASTM D1331 is broken into two separate sections based on the liquid mixture being tested. ASTM D1331 method A applies to aqueous solutions containing surface-active agents. It includes water with two or more surfactants added. ASTM D1331 states that it "is also applicable to nonaqueous solutions and mixed solvent solutions." This includes electrolytes. ASTM D1331 applies to two-phase mixtures. Two-phase mixtures include a water and surfactant mixture containing air in the form of foam or bubbles. Two-phase mixtures include solid particles with the aqueous mixture. ASTM D1331 states "more than one solute component may be present, including solute components that are not in themselves surface-active." This allows for the surface tension testing of soaps when it includes artificial colorings, scents or skin conditioners. Surface tension testing methods do not change when multiple surfactants are included in the mixture.

    Read more: ASTM D1331 Methods | eHow.com http://www.ehow.com/info_8694874_astm-d1331-methods.html#ixzz2DivCVGeX
     This method applies to both aqueous and non-aqueous solutions
    ASTM D1331 is broken into two separate sections based on the liquid mixture being tested. ASTM D1331 method A applies to aqueous solutions containing surface-active agents. It includes water with two or more surfactants added. ASTM D1331 states that it "is also applicable to nonaqueous solutions and mixed solvent solutions." This includes electrolytes. ASTM D1331 applies to two-phase mixtures. Two-phase mixtures include a water and surfactant mixture containing air in the form of foam or bubbles. Two-phase mixtures include solid particles with the aqueous mixture. ASTM D1331 states "more than one solute component may be present, including solute components that are not in themselves surface-active." This allows for the surface tension testing of soaps when it includes artificial colorings, scents or skin conditioners. Surface tension testing methods do not change when multiple surfactants are included in the mixture.

    Read more: ASTM D1331 Methods | eHow.com http://www.ehow.com/info_8694874_astm-d1331-methods.html#ixzz2DivCVGeX
  • ASTM D1590; Surface tension of industrial water and Industrial waste water

The popularity of these ASTM methods require users to perform many of these tests day-to-day and in the process find themselves in situations where they either need to have their tensiometer ring repaired or replaced.  These platinum wire accessories while possessing a very high and durable melt-point can be damaged easily due to mishandling.  Damaged tensiometer rings can effect results so examine the rings routinely and handle with care at all times.

If you do find yourself in a situation where you need a quick repair for your Du Nouy Ring or need to find a replacement let us know.

 
   Tensiometer RingsDu Nouy RingTensiometer Ring

 

 

 

 

 

                          Request Tensiometer Ring Help

 

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About Scientificgear

By Hank Levi on Fri, Aug 31, 2012 @ 10:20 AM

describe the image

Scientificgear LLC provides several targeted areas of service including:

  • Karl Fischer Moisture Titration
  • Titration
  • Surface Tension (Tensiometers and Du Nouy Rings)
  • Contact Angle Analyzers for surface analysis
  • Thermal instruments (WBGT, Conductivity, Heat Flow)
  • Liquid Density Instruments (Benchtop and handheld)
  • Refractometers, Brix Meters

We support companies and organizations in select industries by providing:

  • Technical Support
  • Sales of Instruments
  • In-house and field repair service on select instruments
  • Calibration Service
  • Training and Installation
  • Some in-house testing
  • Manufacture and repair of Du Nouy Rings

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Surface Tension Measurement with the 70545000 Tensiometer

By Hank Levi on Wed, Mar 28, 2012 @ 06:27 PM

Have you ever wondered about how surface tension is measured?  Without getting into the details relating to things like, "What's a dyne per centimeter?", "Du Nouy Ring vs. Wilhelmy Plate", "the effects and force of gravity", "viscosity of liquid", or "temperature",  we decided to put together this short video tutorial to help explain the main components of a popular manual tensiometer (70545000) and how the instrument works.  We think seeing how a basic manual tensiometer measures surface tension is helpful in gaining a better understanding of the big picture.

CSC Tensiometer Model 70545 Interfacial from Scientificgear on Vimeo.

 

SOME QUICK FACTS ABOUT SURFACE TENSION AND HOW TENSIOMETERS HELP

APPLICATIONS OF SURFACE AND INTERFACIAL TENSIONS: Surface and Interfacial tension measurements are extremely important in the control and improvement of:

  • absorptiontensiometer
  • emulsification
  • osmotic pressure
  • cataphoresis
  • evaporation
  • solubility
  • condenstion
  • miscibility

Industries using dye solutions, producing detergents, clarifying liquids, or sparating ores by the flotation process can obtain greater uniformity and efficiency through close control of surface tension of the process liquid.  A close relationship exists between interfacial tensions of oil-liquid systems and the lubricating value of the oil.  Another major use is determining the sludging condition within a transformer, thereby eliminating costly repairs.

 

 7054570537DuNouy Rings

Created on 03/28/12 at 18:32:35

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Tensiometer Calibration

By Hank Levi on Thu, Mar 01, 2012 @ 03:54 PM

manual tensiometer resized 600Although the CSC Scientific Interfacial Tensiometer is fundamentally very straight forward, it is helpful to have a basic understanding of the operational features and components of the tensiometer.  There are dials, clamps, Du Nouy Rings, and Verniers to consider. 

In this video we show you how to check your calibration using a given weight. 

To conduct this calibration check we assume the tensiometer's tension wire is secure and the unit has the ability to provide a stable reading for your given samples.  Take a look at this short video and let us know if you have questions about the process.

 

Created on 03/01/12 at 15:59:28

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How Much Does a Tensiometer Cost?

By Hank Levi on Mon, Sep 26, 2011 @ 03:37 PM

Tensiometers

 

Tensiometers are instruments used for conducting surface analysis on liquid substances.  Typical applications Tensiometers perform include measuring surface tension, interfacial tension as well as liquid density and Lamella Length on some Tensiometer models.  Some models can also perform other tasks including powder wettability and dynamic contact angle of a solid substrate.  Depending on the types of information the operator is seeking to find one model may be more appropriate than the other.

 

To help prospective users evaluate and compare the different types of models available in the market we have prepared a reference document we call the:

 

"Tensiometer Selection Matrix"

 

This matrix is not necessarily brand specific as it was designed to help those seeking to compare capabilities and prices among popular manual Tensiometer models vs. popular Automatic or "digital" Tensiometer models.

 

We hope you find the Tensiometer Selection Matrix helpful in your search and evaluation of Tensiometers.

 Created on 09/22/11 at 12:43:16

Click here to go to the platinum page

Continue Reading