Viscosity measurement techniques pdf

Knowing the viscosity of a fluid can be quite important when you need to measure viscosity. A e b t, \displaystyle \mu aebt, 2 where a \displaystyle a and b. Viscosity techniques are very popular because they are experimentally simple. The viscosity of newtonian fluids is affected by temperature, pressure, and, in the case of solutions and mixtures, by composition. The accuracy of measurements of viscosity of liquids robert s. These include particle characterization with respect to particle size and shape, specific bet surface area and pore size distribution, stability in dispersions, rheology and zeta potential, density and macroscopic behavior of powder heaps, sorption behavior of porous materials under technical conditions. Shop floor viscometers mainly used in industrial applications to measure viscosity of mostly newtonian types of fluid. Viscosity measurement technique using standard glass burette for newtonian liquids.

The common practice is to calibrate viscometers by a stepup technique, using a series of instruments and test fluids, based on the viscosity of water. Aug 01, 2009 this article reacquaints the reader with the basic concepts and terminology for viscosity and addresses techniques to quantify it. Comparisons of the measured viscosity and surface tension to those predicted using thermodynamic models will also be presented. Marvin institute for basic standards, national bureau of standards, washington, d. While it is difficult to control all factors in the process that can affect a fluids viscosity such as temperature. By measuring the solution viscosity we should be able to get an idea about molecular weight. Hence a single viscosity measurement is not sufficient to describe the viscosity of such materials and the viscosity should be measured over a range of shear rates or stresses, or at least at a shear rate relevant for the process or application of interest. Viscosity is a measure of the resistance of a fluid to deform under shear stress. Inline viscosity measurements can give continuous, realtime readings of a fluids viscosity during processing and consequently, can provide a means to automate the viscosity control of process fluids. The torque exerted by viscous shear on the rotor is. The pac viscopro 2100 is the next generation viscometer for the process industries. Device and method for measuring the viscosity of a fluid g. Viscosity measurement and control has assumed great importance in the process industry.

Viscosity and density measurement methods for polymer melts. On this page, we introduce the different underlying measuring methods of our instruments. An important mechanical property of fluids is viscosity. Viscosity is a measurement of a materials resistance to flow, typically a fluid. Results for a tenth sample intended for use in quantifying the total sulfur in fuel oils are also. Experiment v viscosity of oil by the rotating cylinder. For liquids, it corresponds to the informal concept of thickness. Studies of water in oil emulsions and techniques to measure. The molecular viscosity is a property of the material that depends microscopically on bond strengths. Intrinsic viscosity measurement is typical of an absolute technique and the purpose of this lab is to introduce the problems which are common to such techniques. Introduction viscosity is a quantitative measure of a fluids resistance to flow.

The nine samples span the range of fuel types available. This paper proposes a technique for measurement of viscosity of the given liquid. Viscosity is a measure of a fluids resistance to flow, or more precisely, it is the ratio of the force required to overcome internal friction between layers of fluid shearing stress to the change in speed between layers of fluid velocity gradient. The main viscosity measurement methods are the following. When the pressure dependence of the lowshear viscosity is accurately accounted for, traction and, at times, film thickness cannot be explained by the newtonian assumption. A viscometer also called viscosimeter is an instrument used to measure the viscosity of a fluid. In the metric system, the unit of viscosity is the poise 1 p 1 g cm1 s1, which is subdivided to 100 centipoise cp.

Viscosity, in simple terms, is a fluids resistance to flow. The marsh funnel viscometer measures viscosity from the time efflux time it takes a known volume of liquid to flow from the base of a cone through a. The study of the change in form and the flow of matter. Determination of molecular weight university of cincinnati. Viscosity measurement techniques in dissipative particle dynamics.

Although numerous methods are available for the measurement of viscosity. The criticality of kinematic viscosity measurement prompted the petroleum industry to develop a very precise method, first published in 1937, astm d 445, test method for kinematic viscosity of transparent and opaque liquids. Lack of slipperiness is called as viscosity rheology. Chapter 7 measurement techniques for the shear dependence of. They refer to the different types or coefficient values of viscosity that can be measured in a fluid. For defining viscosity of fluids, newtons law of viscosity of fluid states that the shear stress between adjacent fluid layers is proportional to the velocity gradient between the two layers or you can simply remember that the viscosity if the resistance to flow. Zeroshear viscosity measurement necessitates the use of a highly sensitive instrument that can impart very small stresses and measure incredibly low shear rates. Viscosity measurements are made at two separate speeds, normally an order of magnitude apart, such as 50 rpm and 5 rpm. T 230 om08 viscosity of pulp capillary viscometer method 2 2. Viscosity can be thought of as a resistance to flow, with highly viscous fluids being more resistant to flow.

One of these common viscosity measurement techniques is the falling sphere viscometer shown in figure 3 sutterby, 1973. The term kinematic simply means that the measurement is made while fluid is flowing under the force of gravity. The vi scosity shear viscosity of a newtonian liquid is normally measured by a relati ve technique in an instrument calibrated using a liquid of known viscosity. With an installed base of over 175,000 densitometers and viscometers worldwide, we are at the forefront of concentration and density measurement. Falling sphere falling cylinder falling methods in opaque. Physical systems and applications as diverse as fluid flow in. The different types of viscosity measurement devices are explained, such as portable viscosity testers, falling sphere viscometers, piston viscometers, and u tube viscometers. Knowing the viscosity of a uid is critical when dealing with problems of lubrication. In the paint industry a number of measurement methods, from simple flow cup. What are the different methods to measure the viscosity of.

Density and viscosity meters deliver unbeatable accuracy and performance for applications requiring density, concentration or viscosity measurement. The accuracy of measurements of viscosity of liquids. Ten steps to a better rheological measurement 2005 rheology training seminar ten steps to better rheological measurements 1. Kinematic viscosity measurement techniques for used oils should be investigated, and the differences between the methods should be considered. Laboratory formation techniques were examined in 4 apparatuses. Viscosity measurements of the ionic liquid trihexyl. The fork density meter fdm is the latest development in direct insertion density and concentration. Principles of viscosity measurement bykgardner catalog 20102011 pdf. Though there are several different techniques for measuring this parameter, each appropriate to specific process conditions, selecting the right one is still difficult. Measuring the different types of viscosity with viscometers.

Roach and henein 3,4 have developed a new method enabling the simultaneous measurement of surface tension, viscosity, and density in one run for. Most popular viscometers to measure shear viscosity are 1. In this study two main groups of viscosity measurement techniques are used to measure the viscosity of a simple fluid using dissipative particle dynamics, dpd. The viscosity of a fluid is a measure of its resistance to deformation at a given rate.

An important concept, sometimes forgotten, is that a materials viscosity is not a singlepoint measurement, but often depends on a number of factors. A weight, w, is used to drive a rotor that is partially submerged in a sample of liquid. There are several types of viscosity measurement devices. The sr method was found to be useful for very low viscosity materials as yield stresses can be measured accurately as low as 4x104 pa. The type of viscosity yielded by your viscometers measurements depends on the kind.

The fluid is stationary in a tube and a sphere of known diameter and density is dropped into the tube. The most viscous and stable emulsions were produced in the highest energy devices. In this paper, a technique is proposed for measurement of viscosity using the principle of dispersion of incident light with variation of liquid viscosity. Image of the liquid tank which is filled with liquid whose viscosity is to be measurement. Pdf viscosity measurement technique using standard glass. The standard metric units in use for mass and volume respectively are grams and milliters or. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Viscosity the resistance of a fluid to shear or tensile stress is an indispensable measurement in fluid analysis. Information about the scientific background of the glass viscosity is available in an online course viscosity by richard k. Understanding the role of viscosity, and measuring it, is key to correctly analyzing many engineering situations. Viscosity measurements of aviation turbine fuels energy. Viscosity can be measured using two different approaches. There is a way to correlate viscosity measurements made with dynamic and kinematic methods for materials that are newtonian, using the following equation.

They measure the torque and the deflection angle of the measuring bob. Kinematic viscosity has been measured for nine separate aviation turbine fuel samples. The viscosity value at 5 rpm is divided by the viscosity value at 50 rpm. Viscosity is a critical property of a fluid, and monitoring viscosity is highly essential to oil analysis. Objectives for rp15 the objectives of the project are. Following are the various methods used to measure the viscosity of a fluid. A comparison of surface tension, viscosity, and density of. Lakesa department of engineering physics, engineering mechanics program, university of wisconsinmadison, 147 engineering research building, 1500 engineering drive, madison, wisconsin 537061687 received 23 july 2003. In the characterization lab two techniques for determination of molecular weight are introduced, intrinsic viscosity and use of the gpc. Viscosity measurement ubbelohde viscometer, for measuring viscocity of dilute solution upper and lower level measure the flow time t, of solution, drop from upper level to lower level h krt k viscometer constant r density of solution t flow time if, t time for solution to time for solvent r ro dilute solution ro solvent density. To measure the rheological properties of a material, rheometers are used. Experiment v viscosity of oil by the rotating cylinder method. Viscosity measurement purpose the purpose of this experiment is to measure the viscosity of a glycerinwater mixture with a thomasstormer viscometer. The ds method was found to be useful over a wide viscosity range and was especially practical for testing high viscosity semisolid materials such as grease.

Viscosity of pulp capillary viscometer method revision of. Inline viscosity measurements chemical engineering page 1. In the first method, a microscopic definition of the pressure tensor is used in equilibrium and out of equilibrium to measure the zeroshear viscosity and shear viscosity, respectively. Kinematic, dynamic, relative, apparent, absolute when dealing with viscosity measurements using a viscometer, you will likely come across these words. The sample provides resistance or a reset torque to the setting and the resulting. Studies of water in oil emulsions and techniques to. This means that in a viscosity measurement the rheometer presets a certain current that correlates to a defined torque. Motor oil, for example, has its viscosity rated as well as how. Capillary viscometer this method is based on using capillary tubes and the time it takes for a volume of l. Jul 29, 2016 viscosity, in simple terms, is a fluids resistance to flow. Viscosity measurements of the ionic liquid trihexyltetradecylphosphonium dicyanamide p 6,6,6,14dca using the vibrating wire technique.

Shear viscosity is a measure of resistance to isochoric. General instructions for glass viscosity measurements are given in iso 78841 1. In for the simplest case of newtonian fluids, viscosity measurement is a. Pdf in this study two main groups of viscosity measurement techniques are used to measure the viscosity of a simple fluid using dissipative particle.

Our original goal was to compile a comprehensive reference book of common inservice oil analysis techniques to help readers understand and choose the right technique and. The procedure gives two alternative techniques for dissolving the pulp sample. Instruments which measures the viscosity are called as viscometers. Thus, a rheometer can be considered as a special type of viscometer. Examples of rheology testing techniques viscosity testing. Viscosity measurement and applications what is viscosity viscosity is an important property of fluids which describes a liquids resistance to flow and is related to the internal friction within the fluid.

An image processing technique for measurement of liquid viscosity. In this equation, you need to measure the density of both the sphere, p s, and the liquid, p l, it is passing through. For the purpose of this paper, the focus will be on techniques available for use with a rotational rheometer, of which there are several available. By incorporating the oscillating piston method, which is an industryproven sensor technology, the viscopro 2100 is the best choice for applications requiring fast, realtime analysis with reliable data that correlates tightly with laboratory results. An interesting technique to measure the viscosity of a liquid using a quartz crystal. Viscosity measurement series constanttemperature baths for viscometers glass viscometers as per jis k 2283 3000 made in japan as per jis k 2283 3000 along with the growth of the petrochemistry, polymer chemistry, and other industries involving viscous materials, viscosity measurements are increasingly being performed for a variety of fluids. Guide to measuring oil viscosity 2 measuring kinematic viscosity gravimetric capillary the most widely used technique for measuring kinematic viscosity is the use of a gravimetric capillary that is temperature controlled, usually 40 c for single grade oils, and both 40 and 100 c for multigrade oils. For a pseudoplastic material, the ratio of the two viscosities is a number that is greater than 1. Assess the viscosity of your sample when a variety of cones and plates are available, select diameter appropriate for viscosity of sample low viscosity milk 60mm geometry medium viscosity honey 40mm geometry high viscosity caramel 20 or 25mm geometry examine data in terms of absolute instrument variables.

Viscosity can be conceptualized as quantifying the internal frictional force that arises between adjacent layers of fluid that are in relative motion. Viscosity measurement techniques in dissipative particle. For this reason airbearing rheometer such as our ar2000 is a necessity for measurement of zeroshear viscosity. A rule of thumb is that a stable emulsion is one which has a viscosity at least 100 times its starting oil viscosity and this viscosity increases upon sitting over a 5day period. In addition our apparatus was furnished with a system for evenly heating the oil to a variety of temperatures allowing us to investigate the e ects of heat on viscosity.

This chapter discusses measurement techniques for the shear dependence of viscosity at elevated pressure. Pdf viscosity measurement techniques in dissipative. The radius of the sphere, a, can be found by measuring the circumference of the sphere and dividing that by 2. It has been a few years since the publication of the first edition of spectro scientifics inservice oil analysis handbook. The objective of the proposed technique is to design a non contact technique to analyze the characteristics of dispersed image using image processing for the light incident on liquid whose viscosity is to be measured. For liquids with viscosities which vary with flow conditions, an instrument called a rheometer is used. Pdf although there are several approaches to measure viscosity of liquid foods in the literature, the successful selected technique depends. Density is mass per unit volume of an object and is designated with a p. Solids are said to have an elastic response, and can resist. Current commonly used viscosity measurement techniques require that the fluid comes into contact with a solid material. Pdf suitability of viscosity measurement methods for liquid food. Many studies have been done on measuring viscosity by using different techniques.

The effect of pressure and temperature on the viscosity of gases is illustrated in fig. Jan 20, 2015 measurement of shear viscosity depends upon dynamics of shear force acting upon fluid either newtonian non newtonian. I oscar viscometer, a sealed can of fluid was oscillated torsionally, and by clever measurement techniques it was possible to measure both viscosity and elasticity in the sample. This result has the same form as the widespread and accurate empirical relation. Survey of previous measurements most absolute measurements of viscosity which have aimed at an accuracy of better than 1 percent have been made on water. The objective of the proposed work is to implement an image processing technique for measuring the rate of change of liquid level. Understand the variables in the viscosity equation. Viscometers only measures under one flow condition. A comparison of surface tension, viscosity, and density of sn. Besides these two traditional methods for measuring viscosities, a couple of studies also introduced the technique of isothermal compression for alloys in the semi. Method and device for measurement of dynamic viscosity iopscience.

May 01, 20 there is a way to correlate viscosity measurements made with dynamic and kinematic methods for materials that are newtonian, using the following equation. Pdf measurement and calculation of the viscosity of metals a. Six types of devices used to measure viscosity from cole. Density is a measure of the compactness of matter within a substance and is defined by the equation.