The vi is calculated from the viscosity of the polymer in oil solution at 40 c and at 100 c. Model for the viscosity and thermal conductivity of refrigerants, including a new correlation for the viscosity of r4a. Such viscosity index data may be considered as suitable for information only and not for specification purposes. The higher the vi value, the less the drop in viscosity as the oil warms up. The viscosity index, commonly designated vi, is an arbitrary numbering scale that indicates the changes in oil viscosity with changes in temperature. In other words, the shear stress divided by the rate of shear strain is constant for a given fluid at a fixed temperature. It is mostly used to characterize the viscosity temperature behavior of lubricating oils. Most processes are based on the use of fluids either as raw materials, reagents, or heat transfer media. It is defined as the internal frictional resistance of a liquid to the application of a pressure or a shearing stress. The viscosity index improver according to the present invention comprises a hydrogenation product of a copolymer which contains a a structural unit derived from an aromatic vinyl compound and. Molasses, for example, has a greater viscosity than water. Hvm 472 viscometer automated multirange capillary viscometer the herzog multirange viscometer hvm 472 determines kinematic viscosity of transparent and opaque liquids. In this book, we will see many examples of processes where the rates of heat transfer, mass transfer and chemical reaction between. The temperatures used for reference are 100 and 210f.
We provide a broad range of viscosity standards and flash point reference materials to customers across various industries. The less the viscosity is changed by temperature, the higher the viscosity index. Lubrizol is well known for its history of leading lubricant additives. The viscosity index is calculated by the following formula. Viscosity, texture, powder 2015 ametek brookfield pdf. They help lubricant blenders achieve desired rheological properties, such as reducing the tendency of a lubricants viscosity to change when subjected to temperature fluctuations to protect equipment at temperature extremes.
The use of any of the calculators results is at the users sole risk. For many fluids the tangential, or shearing, stress that causes flow is directly proportional to the rate of shear strain, or rate of deformation, that results. The viscosity index vi is an arbitrary, unitless measure of a fluids change in viscosity relative to temperature change. Viscosity index vi is a measure of how oil viscosity changes with variations in temperature. The detergent inhibitor di andor viscosity modifier vm remain unchanged when interchange base oils are tested, except as provided by the acc code. Moreover the instrument is convenient to manipulate. Viscosity improvers supplied as solids and liquids. The concept of viscosity fluid flow plays a very important part in the processing of materials. Method d 227074 was prepared in compliance with worldwide agreements.
This publication is intended to replace the previous viscosity index tables. How can i calculate the viscosity index of an unknown oil. Viscosity, resistance of a fluid to flow or a change in shape. The smaller the difference in viscosity at low 40 c and at high 100 c temperatures, the higher the vi number or index obtained. Viscosity index vi is one approach used wid ely in the lubri cating field to assess the variation of viscosity with temperature. Pdf one of the requirements of engine lubricating oil is that it must have a low enough viscosity at low temperatures to assist in cold starting and a. Viscosity index viscosity index vi defines the viscosity relationship with temperature. Viscosity index improvers are commonly used in multigrade engine oils, gear oils, automatic transmission fluids, powersteering fluids, greases and some hydraulic fluids. Pdf how polymers behave as viscosity index improvers in.
These new tables are based on astm method d 227074 for calculating viscosity index from kinematic viscosity at 40 and 100c. It also applies to fluids like engine and automatic transmission oils, gear lubricants, and powersteering fluids. Understanding the sae motor oil viscosity standard what is motor oil viscosity. Complete performance documentation is required for the original passenger car motor oils pcmo. Calculator for viscosity index vi according to astm d2270 and iso 2909. The measurement and control of the viscosity and density ensures an improved combustion efficiency preventing engine damage and reduction of fuel and maintenance costs. The lower the viscosity index, the more the drop in viscosity as the oil warms up. Like friction between moving solids, viscosity transforms kinetic energy of macroscopic motion into heat energy. Knowledge of a materials rheological characteristics is valuable in predicting its pourability, its performance in a dipping or coating operation, or the ease with which it may be handled, processed, or used. Standard practice for calculating viscosity index from.
The dynamic viscosity describes the flow behavior of liquids. Viscosity, resistance of a fluid liquid or gas to a change in shape, or movement of neighbouring portions relative to one another. Compact density meter cdm gas density meter gdm fork density meter fdm gas specific gravity. The scale of viscosity index is numerical in nature, with zero being the most susceptible to changes in viscosity. The greater the viscosity index vi, the smaller the change in fluid viscosity for a given change in. The calculator on this site is for informative purposes only and we make no claims as to the accuracy, completeness or fitness for any particular purpose of the results produced by our calculators. Some people think the viscosity index is incorporated in the iso viscosity grade, but it is not. The viscosity index improver according to the present invention comprises a hydrogenation product of a copolymer which contains a a structural unit derived from an aromatic vinyl compound and b a structural unit derived from a conjugated diene, wherein b1 a farnesenederived structural unit is contained in an amount of 1 to 100 mass% and.
Viscosity of refrigerants and other working fluids from residual entropy scaling. These are the current methods for calculating the vi for petroleum products used in civil and military applications. Viscosity index improvers are available with permanent shear stability pssi values between 25. Viscosity index is an arbitrary measure for the change of viscosity with variations in temperature. Viscosity index improvers and polymer architectures 2 linear comb multi star hyper branch dendrimer increasing viscosity influence increasing shear stability fact vmsviis are additives that minimize the change of fluid viscosity with temperature popularempirical belief change in size rg, rh is the mechanism. How to understand the technical data we provide on every. The reciprocal of the viscosity is called the fluidity, a measure of the ease of flow. Shows the evaluation of effects of pressure lubricants. It stands alone as an independent lubricant performance differentiator.
Viscosity of mixed refrigerants r404a, r407c, r410a, and r507a. Friction at the molecular level viscosity is, essentially, fluid friction. Petroleum products calculation of viscosity index from kinematic viscosity 1 scope this international standard describes two procedures for calculating the viscosity index vi of petroleum products and related materials, such as lubricating oils, from their kinematic viscosities at 40 c and 100 c. The lower the vi, the more the viscosity is affected by changes in temperature. The molecular viscosity is a property of the material that depends microscopically on bond strengths. A base oil interchange obtained under these guidelines applies to a single pcmo formulation.
Understanding viscosity index improvers lubrication. Dont ignore viscosity index when selecting a lubricant. For many years, weve provided the most extensive portfolio of advanced additive technologies that help our customers develop and market their products, whether their goal is to offer basic specification meeting lubricants or the most differentiated and premium products on the market. Petroleum products calculation of viscosity index from. Viscosity versus viscosity index mobilehydraulic tips. Viscosity modifier vm viscosity index additives are. The viscosity index test astm d 2270 is based on the kinematic viscosity of the oil at 40c. They allow the fluid to flow more freely at a lower temperature so it can reach the bearings quicker. Viscosity index is a dimensionless number that represents how the viscosity of a hydraulic fluid changes with temperature. Greek letter eta is normally given in millipascalseconds mpas and is usually determined by using a rotary viscometer.
We commonly refer to high viscosity fluids as being thick and low viscosity fluids as being thin. The viscosity index vi allows for comparison of the viscosity behavior of different oils. Since every fluid is different, its reaction to the same temperature is different. Thus 0 indicates an oil with the greatest change over a certain temperature while 100 indicates an oil with the least change over a certain temperature. Viscosity improvers are polymer additives that reduce the impact of increasing temperature on the viscosity of lubricants. In 2000 international refrigeration conferences at purdue university.
Vi viscosity index vi is an empirical measure of how much the viscosity of a lubricating oil changes with a change in temperature. Viscosity index numbers are devised on a scale of 0 to 100, which indicates the extent of viscosity change. Td114cng rev 102018 technical data 102 barton street, st. These two values are used to calculate the vi according to astm d2270. Apr 16, 2020 viscosity index vi is a scale used to measure how much an oils viscosity, or resistance to flow, changes depending on its temperature.
Viscosity index is a measure for the change of kinematic viscosity with temperature. Too often the viscosity index vi is disregarded as a lubricant selection parameter. Calculated carbon aromaticity index ccai is the index for the ignition quality of residual fuel oil and is calculated from density and viscosity of the fuel. This means that for all liquids as the temperature increases, the liquids vis cosity decreases. Those were based on 100 and 210f as reference temperatures. Irgaflo 1100 v page 1 of 3 technical information lubricant additives tievo march 2010 basf irgaflo 1100 v viscosity index improver general irgaflo 1100 v is an alkyl methacrylate copolymer in a highly refined mineral oil providing exceptional shear stability even under the severe krl 100 hours test conditions.
Generally speaking, the less it changes, across a range of temperatures, the better. Permissions to reprint documents can be acquired through. A high vi can be interpreted as meaning that a polymer increases the viscosity of the fluid without polymer proportionately more at high temperatures than at low temperatures. Triiso distributes a wide range of viscosity index improvers vii to produce high quality lubricants. The purpose of this manual is to aid the machine operator in the selection of suitable. The vi scale goes from 0 to 100, with 0 being the worst, and 100 being. D2270102016 standard practice for calculating viscosity index from kinematic viscosity at 40 c and 100 c. The easy to operate hvm 472 includes 2 multirange capillaries with 100 fold measuring range, requires only 18 ml, and delivers precise results. The vi scale goes from 0 to 100, with 0 being the worst, and 100 being the best. So specifically with regard to suspension, the greater the vi, the more consistent the damping will be over a large temp change. In addition to providing a lubricating and cooling bath for the dampers and bushings of the fork and shock to function in, the suspension fluid is the medium that is used to provide damping in a modern system essentially, the oil is forced through an orifice or past a spring loaded shim to creating a resistive force to the action of the shocks. One analyzer unit measures the kinematic viscosity at a temperature of 40c and the other at a temperature of typically 100c.
One reason is simply because it is poorly understood. Hydraulic fluids and lubricants, technical information danfoss. Astm d2270 102016 standard practice for calculating viscosity. It is the rate of change of viscosity between 2 temperatures. This precision is sufficiently good for works control, has been satisfactory for trading, and is within the requirements demanded by efficient lubrication. There are two standard procedures to calculate the viscosity index.
The viscosity index is a measure of viscosity fluctuations with changes in temperature. How polymers behave as viscosity index improvers in. Viscosity index vi is a scale used to measure how much an oils viscosity, or resistance to flow, changes depending on its temperature. Simply put viscosity is a physical property of a fluid or gas that reflects its tendency to flow. Astm d227004 standard practice for calculating viscosity index from kinematic viscosity at 40 and 100c. Our standards calibrate and verify the performance of glass capillary viscometers, automated kinematic viscometers, rotational viscometers. Appendix eapi base oil interchangeability guidelines for. The bartec benke viscosity index process analyzer vi4 consists of two viscosity process analyzer units. Your triiso technical sales representative is available to assist you in the selection of the appropriate chemical that will provide the specific properties you are trying to obtain.
Since 1938 cannon instrument company has been a leader in viscosity measurement. Remember, viscosity is a fluids measure of resistance to flow and shear. Standard practice for calculating viscosity index from kinematic viscosity at 40 and 100c1 this standard is issued under the. Click to request samples or quotes of viscosity index improvers. Additional information on the various types of viscometers and their operation can be found in the physical measurements training manual, navair 1735qal2. Viscosity index improvers resist the thinning that occurs in a lubricant as the temperature is increased. The hfvm viscomaster is a high performance, multivariable viscosity meter designed for the measurement and control of heavy fuel oil hfo that supply engines, turbines and burners in marine and power applications. In 16th international refrigeration and air conditioning conference at purdue, july 1114, 2016.
The lower the vi, the greater the change of viscosity of the oil with temperature, and vice versa. The viscosity index is important both for new oils and for inservice oils. Vi l u l h 10 where, vi is viscosity index u is the kinematic viscosity of oil of interest l and h are the kinematic viscosity of the reference oils. Cn104704090a viscosity index improver, method for producing. The vi scale was set up in the 1920s by the society of automotive engineers sae. Viscosity modifiers vms are polymers that are key ingredients in many lubricating oils.
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