Huazheng HZ1731 User manual

HZ1731
Full Automatic Surface Tension
Tester
User Manual
Huazheng Electric Manufacturing (Baoding) Co., Ltd

Dear us er:
Th an k you for choosing HZ1731 Ful l Autom atic Sur fa ce Ten sion
Tester.
We hope that this instrume nt can make you r work easier and more
en jo ya bl e, so that you can get th e fee li ng of office aut om at ion in the test
an d an al ys is work.
Before us ing the inst rument, pl ea se re ad this manual, an d opera te and
maintain the instrume nt accordi ng to the ma nu al to pro lo ng its se rvice li fe .
"Just a light press, the test will be compl eted auto ma ti ca lly" is the
op er ating cha racteristics of this instrument.
If you are sat isfied wi th this inst rument, ple as e tel l yo ur co lleagues;
if you are not satisfie d with this ins trum ent, pl ea se call [phone] to
te ll you to ser ve you at all times- Baoding Huazheng Electri c Manufactu ring
Co. , Lt d., our comp an y will def initel y make you satisfied!

Contents
I.Summary................................................................................................................................................ 4
II.Instrument Introduction....................................................................................................................... 6
III.Instrument Operation........................................................................................................................10
IV.Attention............................................................................................................................................. 14
V.Appendix............................................................................................................................................. 15

I.Summary
This is HZ1731 full automatic surface tension tester including platinum plate method and
platinum ring method produced by . The surface tension is a basic property of liquid,
especially surfactant aqueous solution. Can measure the surface tension value of various
liquid quickly and accurately with physical method instead of chemical method. It has a
wide range of application. It can measure surface tension in hydropower sector to
strengthen supervision on the quality of insulating oil; it can measure and analyze the
surface tension value of various liquid in petroleum and chemical industry, scientific
research and education department.
1.1 What is the surface tension
Surface tension is the tension of liquid surface on any boundary line along the surface
due to the unbalanced molecular attraction. The resultant force on a molecule by
surrounding molecules inside the liquid is 0. However, that on the surface is not zero
because attraction on the molecule on the surface by gas phase molecular in the upper
space is smaller than that by the internal liquid phase molecule. The resultant force is
perpendicular to the liquid inside, resulting in automatic contracting trend in the surface of
the liquid and this contraction force is called surface tension.
Molecules inside the liquid are close to each other, maintaining a balanced distance
between molecules with attraction on a little farther distance and repulsion on a little
closer distance. It makes liquid molecules can only vibrate and rotate near the equilibrium
position unlike gas molecules that can diffuse infinitely. Liquid molecules near the surface
are only affected significantly by liquid inside. With uneven stress, the molecular in higher
velocity can easily escape from liquid and become steam thus resulting in molecule

distribution in the surface layer (a thin liquid layer contacting gas ) is sparser than internal.
Intermolecular repulsion in surface layer decreases as the distance between each other
increases. Intermolecular attraction prevails in surface layer. Mutual traction of any two
parts in surface layer prompts a shrinking trend in surface layer. The liquid surface tends
to reduce as much as possible due to the effect of surface tension, so the small droplet in
the air is in spherical shape.
1.2 Platinum plate method)
When the platinum plate is immersed in the liquid to be measured, the surface tension will
occurs around the platinum plate. The surface tension of the liquid will try to pull plate
down. When surface tension of the liquid and other related stress are equal to the
equilibrium force, the platinum plate will stop. At this time, the balance sensor will measure
the immersion depth, and convert it to the liquid surface tension values.
Steps:
(1) Raise the platform;
(2) When the bottom of the platinum plate contacts with the liquid surface, the equilibrium
value is measured by the sensor and converted to the surface tension value to display.
1.3 Platinum ring method
A circular membrane between testing part and the liquid sample will be formed with this
method.
Steps:
(1) Immerse the platinum ring gently into liquid inside.
(2)The platform descends and then a bubble film forms below the platinum ring and
eventually leaves it.
(3)The equilibrium value is measured by the sensor and converted to the surface tension
value to display.
1.4 Comparison
①The platinum plate method measures the change of liquid surface (or interface) tension
over time. Platinum plate is always contacting with the liquid to be tested and as long as
the liquid surface tension changes, the test value will change. The curve of surface
tension over time can be observed with data processing software.
②The platinum plate method can easily measure the surface tension of medium and high
viscosity liquid; The platinum ring method requires the ring to ascend and the ring is acted
upon surface tension and viscous force in that process.
③The platinum plate method has high precision. Platinum plate is harder to be deformed
than ring. Irregular and uneven round ring may affect test precision.