The CSC duNouy Tensiometer is a laboratory Instrument for the purpose of determining the strength of a liquid surface. Test is used in coatings and industries. Applications are also in chemical, pharmaceutical and electric power applications.

1. CSC Scientific Company
DuNouy Tensiometer

2. DuNouy Tensiometer
• The CSC DuNouy Tensiometer helps
decorative and hard chrome platers
meet the EPA regulations on chromium
emissions.
The regulations state that there is a
direct relationship between surface
tension and chromium emission.
• The interfacial tension test is the most
valuable single test that can be used to
evaluate a turbine oil.
It is generally agreed that when the
interfacial tension is between 15 and
20 dynes/cm, deposits may or may not
be forming in the system.

3. DuNouy Tensiometer
•The Precision DuNouy Tensiometer
measures upward surface tension.
•The Interfacial DuNouy Tensiometer
measures both upward and downward
forces.
Both units are delivered complete with platinum iridium ring
and carrying case allowing you to get rapid measurement in
15 to 30 seconds right out of the box.

4. Applications
•paints, coatings and inks;
•chrome, nickel, and brass plating;
•soap;
•surfactants;
•emulsions;
•crude and transformer oils.
•universities and technical centers as an
important instrument for scientific studies.

5. DuNouy Tensiometer
•RAPID MEASUREMENT
Ring method allows readings to be made in 15-30 seconds
•DIRECT READING
Equipped with circular scale in dyne/cm - No Calculations needed.
•REPRODUCTIBLE RESULTS
Accurate readings can be reproduced within +/- 0.05 dyne/cm
•PORTABILITY
Compact unit comes with a carrying case for easy transport
•STABILITY
Mounted on a cast tripod support with convenient leveling screws

6. Intermolecular forces as they
effect Interfacial Tension
A layer of molecules on an oil’s
surface are in contact with air
(Fig 1) the molecules are more
strongly attracted from below
because the molecules in the air
are further apart (the attraction is
inversely proportional to the
distance between the molecules).
A similar imbalance occurs
between two immiscible liquids
such as oil and water; in this
case the phenomenon is called
interfacial tension.

7. Measurement Techniques
The most common method of
measuring surface /interfacial
tension
In the test (Figures 2 and 3), the
force required to lift a horizontal
platinum wire ring away from the
oil’s surface is measured either
directly (surface tension) or at an
oil/water interface (interfacial
tension).
The unit of measure for surface
tension is dynes per centimeter
(equal to mN/m).

8. Interfacial Test

9. Comparing Oil Oxidation Sensitivity Using
Interfacial Tension and Neutralization Number
When oils oxidize they
form soluble and
insoluble hydrophilic
compounds. Many of
these compounds
can alter the IFT of a
lubricant long before
there is any
noticeable change in
acid number or
viscosity (Fig 4).

10. Different ways Surface Tension
is Measured

11. Wilhelmy Plate

12. DuNouy Ring

13. How is Surface Tension Measured?

14. CSC Rings

15. CSC DuNouy Tensiometer

16. DuNouy Precision Tensiometer
How it works

17. DuNouy Interfacial Tensiometer
How it works