Falling ball viscometer aim the purpose of this experiment. Viscosity and viscoelastic behavior of resins are very critical in. Pdf on sep 1, 2017, riady siswoyo jo and others published development of lowcost visionbased falling sphere viscometer find, read. Viscometer uses the simple but precise hoppler principle to measure the viscosity of newtonian liquids by measuring the time. Brookfield viscometers rheometers falling ball viscometer. Rotational viscometers use the concept of torque to measure the effort required. A commonly used apparatus in undergraduate physics laboratory environment is the falling sphere viscometer or stokes viscometer.
A new method of accurate calculation of the coefficient of viscosity of a test liquid from experimentally measured terminal velocity of a ball falling in the test liquid. Stokes law is the basis of the falling sphere viscometer, in which the fluid is stationary in a vertical glass tube. There are several types of viscosity measurement devices. Homework statement a falling sphere viscometer measures the viscosity of a liquid from the terminal velocity of a tiny, falling sphere. If correctly selected, it reaches terminal velocity, which can be measured by the time it takes to pass two marks on the. Viscosity of liquid for falling sphere viscometer physics. Haake viscometer standard operating procedure updated sept 10, 2014 general information viscosity is a measure of the resistatnce of a fluid which is being deformed by either shear stress of tensile stress.
The brookfield falling ball viscometer measures viscosity in accordance with the test method defined in din 53015 hoppler principle to measure the viscosity of newtonian liquid by measuring the time required for a ball to fall under gravity through a samplefilled tube. Reynolds number, and measuring liquid viscosity home natural sciences chemisty stokes law. Pdf development of lowcost visionbased falling sphere viscometer. Us20160528a1 fallingpiston viscometer and methods for. Attach vertical pole to the base using the wrench provided in the case b. The viscometer in the viscosity control system 100 is a falling piston viscometer 200. These viscometerstubes are suitable for measuring transparent liquids. R viscosity measurements with the falling ball viscometer 1.
By using a falling ball viscometer we can determine the sphere s terminal velocity and also calculate the drag force using equation 5. An automatic falling cylinder viscometer for high pressures was also developed by irving and barlow. Falling sphere viscometer constant temperature bcth 25t0 005 c j lloyd sutterbyt process fundamentals research laboratory, the dow chemical company, midland, michigan 48640, usa receiaed 6 nogember 1972, in fiiial form 24 may 1973 abstract a wide range, precision falling sphere viscometer is described. Start stop watch when the ball reaches to the first marks on the tube, and measure the time between the two marks. Currently, the whole process of determining the viscosity of a.
Viscosity of newtonian fluids using haake falling ball. Pdf design of a high precision falling ball viscometer. Mar 27, 2014 by using a falling ball viscometer we can determine the spheres terminal velocity and also calculate the drag force using equation 5. Utube viscometers modified ostwald viscometers psl. Feb 19, 2015 homework statement a falling sphere viscometer measures the viscosity of a liquid from the terminal velocity of a tiny, falling sphere. Design of a high precision falling ball viscometer. The amount of time it takes from release to a specific point in a cylinder gives you a measure of resistance that is the fluid viscosity.
Less common alternatives for measuring viscosity include the falling ball and falling piston viscometers. Sav09 the sav09 integrates the original falling rod visometer technology with userfriendly computer software designed to more accurately test, catolog, store, and formalize test data with the click of a button. Measurement of viscosity in a vertical falling ball viscometer. Kershaw instrumentation llc falling rod viscometer. The different types of viscosity measurement devices are explained, such as portable viscosity testers, falling sphere viscometers, piston viscometers, and u tube viscometers. The determination of viscosity with a capillary viscometer is based on poiseuilles law and. For most of the measurements this is fine since the spheres reach terminal velocity and so it is easy to calculate the viscosity from. Stokes law, reynolds number, and measuring liquid viscosity. Measurement of liquid viscosity coefficient using a falling sphere can reveal related physical phenomena clearly. Viscometers visual encyclopedia of chemical engineering. Apr 27, 2015 falling sphere viscometer the falling ball viscometer is based on stokes law. The principle of the viscometer is to determine the falling time of a ball of. This type of viscometer is used for measuring newtonian fluids. The action of a viscometer with a sphere that moves in the medium under investigation is based on stokes law.
Falling sphere viscometer article about falling sphere. Hello, i have recently conducted an experiment to measure the viscosity of some liquids using the falling sphere method and a high speed camera. Haake viscometer standard operating procedure updated sept 10, 2014 viscometer operating procedure 1. Viscosity measurement using ostwalds viscometer amrita. Viscosity coefficient is one of the important properties of liquid. Falling ball viscometers determine the viscosity of a newtonian fluid by measuring the velocity of a ball moving through the fluid.
A student researched lab analysis about stokes law, reynolds number, and measuring liquid viscosity. An instrument designed to measure the viscosity of a fluid. Jul 12, 2010 ostwalds viscometer is a traditional viscometer to measure the viscosity of a liquid. The sample should rest at least some 15 minutes in the measuring tube at the test temperature before the measurement is started. Falling ball viscometer article about falling ball. Before starting the measurement, it is better to turn the falling tube up and down at least once in order to enhance temperature uniformity along the tube. The brookfield falling ball viscometer uses the hoppler principle to measure newtonian fluids. Viscosity of newtonian fluids using haake falling ball viscometer. Described herein is a falling piston viscometer which includes a measuring bushing and a piston configured to be slidably receivable inside the measuring bushing. Dont let traditional viscometers get in the way of. Buy utube viscometerstubes, type of modified ostwald viscometers from pslrheotek. Pdf a commonly used apparatus in undergraduate physics laboratory environment is the falling sphere viscometer or stokes viscometer.
Falling ball viscometer principle instrumentation tools. A ball of known dimensions rolls or falls through a closed capillary, which contains the sample liquid. Based on the original falling rod design, this instrument ensures accuracy and repeatability. The lack of information on as a function of reynolds number over the whole range is the only limiting factor in the use of falling ball viscometry to determination of absolute value of. The most common types of viscometer are capillary, rotary, fallingsphere, and ultrasonic. Falling sphere viscometer another method of measuring the viscosity of a fluid is the rotating viscometer figure 4. A falling ball viscometer has a sphere ball that falls down along a tube containing the sample liquid to be measured, and this tube is surrounded concentrically by a tubular jacket for thermal control. Normally, the measurement accuracy of the falling ball method is not high by using a manual stopwatch considering the existing parallax errors of the sphere. One such device determines that a tiny sphere of radius 46. Stokes law can be used to calculate the viscosity of the fluid. In practice therefore, it is common to use a hoppler falling sphere viscometer, which uses a cylinder. In the falling ball viscometer, a spherical steel ball is allowed to fall through a tube containing the solution to be measured. Kershaw instrumentation llc falling rod viscometer, model.
The principle of the viscometer is to determine the falling time of a sphere with known density and diameter within a fluid filled inside glass tube. Supplied complete with iso 17025 certificate of calibration. A standard ball is allowed to fall down this tube over a calibrated distance of 100 mm. Falling ball viscometer is superior in this regard and considerable amount of work has been done in application of falling ball viscometry to measurement of. Feb 02, 20 viscosity of newtonian fluids using haake falling ball viscometer. Nov 16, 2012 hello, i have recently conducted an experiment to measure the viscosity of some liquids using the falling sphere method and a high speed camera.
A sphere of known size and density is allowed to descend through the liquid. Dont let traditional viscometers get in the way of perfect. Find out information about falling sphere viscometer. The forces acting on a sphere falling in a falling ball viscometer consist of force due to gravity f g, force due to the buoyancy of the solution f. The viscometer is meant to approximate an infinitely long column of infinite diameter. Haake viscometer standard operating procedure updated. A closed form solution for falling cylinder viscometers. Analysis a falling ball viscometer is that a sphere ball falls down. The circumferential edge of a first section of the piston in the described falling piston assembly is modified to. Put simply, a piston, or sphere, of known size and density, is lifted and then released into a fluid.
Falling ball viscometer aim the purpose of this experiment is to measure the viscosity of unknown oil with a falling ball viscometer. Falling sphere viscometer synonyms, falling sphere viscometer pronunciation, falling sphere viscometer translation, english dictionary definition of falling sphere viscometer. Haake viscometer standard operating procedure updated sept. Because the feature of this kind of viscometer is vertical to the ground, this study names it as the vertical falling ball viscometer. Stokes law will be verified if the calculated drag force approximates that described in equation 1. A fallingball rollingball viscometer does not measure a liquids flow time, but the rolling or falling time of a ball.
Ostwalds viscometer is a traditional viscometer to measure the viscosity of a liquid. The falling ball viscometer utilizes the simple but precise hoppler principle to measure viscosity. Absolute falling ball viscometer, adapted to the low viscosities of. Falling ball viscometer uses the simple but precise hoppler principle to measure the viscosity of newtonian liquids by measuring the time required for a ball to fall under gravity through a samplefilled tube. The basic concept is to measure the elapsed time required for the ball to fall under gravity through a samplefilled tube inclined at an angle.
The falling ball viscometer is based on stokes law. The falling sphere viscosimeter and drag coefficient unit, hvb, is used to determine dynamic or kinematic viscosities of fluids and the. A lower fluid viscosity results in less resistance to flow, which corresponds to a faster velocity of the moving object. If correctly selected, it reaches terminal velocity, which can be measured by the time it takes to pass two marks on the tube. Viscometer an instrument for the determination of viscosity. Principle the principle of the viscometer is to determine the falling time of a sphere with known density and diameter within a fluid filled inside glass tube. The method applies newtons law of motion under force balance on a falling sphere ball when it reaches a terminal velocity. Falling sphere viscometer the falling ball viscometer is based on stokes law. This type of viscometer consists of a circular cylinder filled by the liquid under investigation. Pdf data acquisition system for a fallingsphere viscometer. Several studies on the falling ball viscometers were conducted with newtonian fluids3, and wealthy fluids in suspended particles 4. Bubble viscometers measure the amount of time it takes a bubble of gas to move through the material whose viscosity is being tested. Falling rod viscometer data sheet frv2000 data sheet. Falling ball viscometers measure the time it takes for a sphere of a known size and density to descend through a stationary liquid.
The falling ball viscometer is based on the measuring principle by hoppler for simple but precise dynamic viscosity measurement of transparent newtonian fluids. In one arm, the bulb a is connected with a fine capillary. Falling ball viscometer is a well developed device for measuring viscosity of a fluid, and the method had claimed in international standards 4, 5. Because this type of viscometer is vertical to the ground, it will be referred to here as a vertical falling ball viscometer. Viscometer definition a viscometer is a tool that is used to measure the viscosity of a material.
Falling sphere viscometer definition of falling sphere. A falling sphere viscometer measures viscosity by capturing the time it takes for a sphere of a known dimension and density to make its way from the top of a material sample to the bottom. The camera magnification is predetermined by photographing a scale immersed in the fall space. Stokes law is the basis of the fallingsphere viscometer, in which the fluid is stationary in a vertical glass tube. May 05, 2016 falling object sphere or piston viscometer.1056 959 1393 593 1346 1288 150 463 467 1406 962 13 255 680 28 287 71 1262 513 711 535 1029 152 656 802 792 245 238 1257 495 838 1309 1027 302 420 1076 806 225