1. Why should viscosity be tested?


The viscosity of silicone oil can vary greatly from 0.65cs to 2000000cs, and the viscosity remains constant in a wide temperature range. Due to the special characteristics of the chemical bond between silicon and oxygen in the polymer chain, compared with some organic polymers, silicone polymers also exhibit excellent thermal stability (up to 250 ° C). Due to its very low surface tension, silicone is very easy to spread on the surface, and has high compressibility compared with different hydrocarbons and mineral oils. Siloxane polymers have good dielectric properties and remarkable shear stress resistance, natural aging, oxidation and hydrolysis capabilities. The basic reason for different viscosities of silicone oil is different molecular weights and different molecular chain lengths. In addition, as a widely used chemical, silicone oil has different applications with different viscosities.


2. Principle and type of viscometer

Viscosity is the physical quantity of internal friction that occurs in the fluid when the fluid flows. It is the ability of fluid to resist deformation and is an important indicator to identify some finished or semi-finished products. Viscosity varies with fluid type and temperature. Generally, there are many types of viscometers, which can be divided into rotary type, capillary type and vibrating type according to the operation mode. Let's introduce their differences and the difference of measurement principle.



A. Rotary viscometer
The common rotary viscometer is cone plate viscometer. Its basic principle is that a synchronous micro motor drives the rotating cylinder to rotate in the measured fluid at a certain rate. Due to the effect of fluid viscosity, the rotating cylinder will lag, and the elastic element connected with the rotating cylinder will produce a certain torsion in the opposite direction of rotation. The torsional stress is measured by the sensor, so as to obtain the viscosity value of the fluid.


B. Ubbelohde viscometer
Ubbelohde viscometer generally refers to a three tube instrument made of glass. It is an instrument that converts the time consumed by gravity falling fluid flowing through the scale line into fluid viscosity under the action of external force. When the fluid flows under the action of external forces, there is tangential internal friction between the flowing liquid layers. If you want to make the liquid pass through the pipe, you must consume some work to overcome the flow resistance. When the flow rate is low, the liquid in the pipe moves along a straight line parallel to the pipe wall. The liquid closest to the pipe wall is actually stationary. The farther away from the pipe wall, the greater the flow speed.


C. Anton Paar Automatic Kinematic Viscometer SVM 2001
Anton Paar has been established for 100 years. Its instrument measurement technology is leading the world. Its test results have reached the SGS certification. Its test volume is small, fast and efficient. The SVM 2001 series of kinematic viscometers are good substitutes for manual glass capillary viscometers. When testing samples, it is no longer necessary to use a stopwatch or constant temperature bath, nor to calibrate more than ten glass capillaries one by one. Simple and fast viscosity measurement can be carried out on various types of samples, including fuel oil, lubricating oil and waste oil, in the range of 15 ° C to 100 ° C. Just fill the sample from the syringe and start measuring, and the results can be obtained within a few minutes. Use a measuring cell to cover from 0.65 mm ²/ S to 30000 mm ²/ Within the whole viscosity range of s, it is unnecessary to replace the capillary tube, and the density, dynamic viscosity and kinematic viscosity results are obtained at the same time.