When the liquid flow by gravity time required for the liquid to pass between two mark a and b through the capillary tube is determined. The method of determining viscosity with this instrument consists of measuring the time for a known volume of the liquid the volume contained between the marks a and b to flow through the capillary under the influence of gravity. The values of co and b shown below are based on a coefficient of thermal expansion typical to that for a mineral oil. Ostwald viscometer, rubber tube with screw pinch cock, relative density r.
Attach the spindle lefthand thread to the viscometer lower shaft by lifting the coupling screw slightly. A weight, w, is used to drive a rotor that is partially submerged in a sample of liquid. The ostwald viscometer is also known as a utube viscometer or capillary viscometer. He defined the idea of catalysis, coined the word mole, and contributed to thermodynamics, electrochemistry, and colloids. Relative viscosity is the ratio of the absolute viscosity of the fluid on the. Change the temperature and calculate the viscosity. Determination of the liquid permeability of consolidated cores experiment 4. Experiment 1 viscosity measurement purpose the purpose of this experiment is to measure the viscosity of a glycerinwater mixture with a thomasstormer viscometer. Calculation of viscometer constants for cannonfenske routine. Utube viscometers modified ostwald viscometers psl. Determination of viscosity of liquid using ostwald viscometer. Viscosity is a measure of the resistance of fluid to an applied stress.
Ostwald viscometer is a commonly used viscometer, which consists of a ushaped glass tube held vertically. Determination of viscosity by ostwald viscometer the viscosity of liquid is. This viscometer may be a reference viscometer driving head at least 400 mm that has been. Viscosity of schiff base prepared as well as of resin was assessed by standardized ostwald viscometer. Another version is the ubbelohde viscometer, which consists of a ushaped glass tube held vertically in a controlled temperature bath.
In industry viscometer and rheometer are traditionally used for the quality control in order to determine these physical features. The rotary viscometer must be adjusted until it is exactly vertical. Put both the viscometer and thermostat into a beaker with water and make sure that viscometer is clamped vertically and check the viscometer with pure water what volume is required to fill the viscometer. The synthetic resin and the schiff base having a concentration ranging from 0. To determine the viscosity and effect of concentration of.
Viscosity measurement includes three virtual experiments. Method a using ostwaldtype viscometer apparatus the apparatus consists of a glass utube viscometer see fig. Plug the metal jack of the power supply into the circular receptacle on the back of the viscometer. The distillates were characterised in part by viscometry. Ostwald viscometer is use to determine viscosity of newtonian fluid. A standard ball is allowed to fall down this tube over a calibrated distance of 100 mm. All liquids appear resistance to flow change from liquid to another, the water faster. Hold it firmly with one hand while screwing the spindle on with the other note lefthand thread. Viscometer in chemical applications viscometer basic information the viscosity rheology describes by means of a measurement the flow behavior of the liquids and gases. Ostwald viscometer was previously calibrated using water. Practical manual shri ramdeobaba college of engineering. Determination of viscosity with ostwald viscometer. This type of viscometer consists of a circular cylinder filled by the liquid under investigation.
The measurement is determined by noting the time required for the fluid to flow a certain distance through tubing of a specific diameter. Ostwald viscometer article about ostwald viscometer by the. Determination of viscosity of organic solvents theory. Borosilicate glass ostwald oil viscometer, thermocap plus capillary viscometer baths, mechanics system 2 physics kit, made. Thus, a rheometer can be considered as a special type of viscometer. Always wear lab coat and gloves when you are in the lab. The measurement of relative viscosity is a easy task. Measurements may be made on bleached cotton and wood pulps. Determination of viscosity by ostwald viscometer the viscosity of liquid is a resistance to flow of a liquid. The viscometer constant is noted on a card included with the product. To determine the viscosity and effect of concentration of unknown solution using a ostwald viscometer. Jul 12, 2010 ostwald s viscometer is a traditional viscometer to measure the viscosity of a liquid. May 14, 2019 determination of viscosity by ostwald viscometer the viscosity of liquid is a resistance to flow of a liquid.
The principle of operation of this viscometer is the same as all other rotational viscometers. The force of friction which one part of the liquid offers to another part of the liquid is called viscosity. The key difference between ostwald and ubbelohde viscometers is that ostwald viscometer is suitable for the measurement of low to moderate viscosity of liquids whereas ubbelohde viscometer is suitable for the measurement of high viscosity of liquids. Ostwalds viscometer is a traditional viscometer to measure the viscosity of a liquid. Do not attempt to operate the viscometer with the shipping cap in place. Amrita virtual lab project website ostwalds viscometer is a traditional viscometer to measure the viscosity of a liquid. Following the invention of the haberbosch process for ammonia, he patented its catalytic oxidation to nitric acid. Supplied complete with iso 17025 certificate of calibration. Apr 16, 2020 the ostwald viscometer is also known as a utube viscometer or capillary viscometer. The viscometer with the sample is immersed in a water bath so that it attains the desired temperature. Newtons law of viscosity, given above, is a constitutive equation like. This might be as simple as a utube viscometer that measures the time taken for a gravitydriven flow to move from one vertical position to another, or a similar situation for flow from the hole at the bottom of a carefully.
Determination of viscosity of organic solvents procedure. Experiment 3 experiment no 3 measurement of viscosity of given. These viscometerstubes are suitable for measuring transparent liquids. Mount the guard leg, if used, spindle protector on the viscometer. Oct 17, 2015 prepare 0%, 30%, 50%, 70%, 90% and 100% solution of glycerin in pure water. Apr 27, 2015 falling sphere viscometer the falling ball viscometer is based on stokes law. Ostwald viscometer, also known as utube viscometer or capillary viscometer is a device used to measure the viscosity of the liquid with a known density. Certain devices use other falling objects than balls, for. Repeat the experiment and record the results take average of results. Viscometer in oil and lubricant applications viscometry of oils and emulsions in all industrial application fields, in which oils, gels and emulsions are pumped, stirred and filtered as well as are treated physically and chemically in product circulations, the flowability of these substances plays a very important plant engineering role. Utube viscometers modified ostwald viscometers psl rheotek.
Lower the viscometer until the surface of the liquid exactly. Ostwald viscometer need a smalldiameter tube capillary measure time of flow of a specific volume through the capillary constant pressure drop across the capillary use poiseuilles equation to calculate viscosity must be calibrated with a known material t b fallingball viscometer measure the terminal velocity of a ball falling in a fluid. The first part of the experiment uses an ostwald viscometer to determine how long it takes a liquid to flow through the capillary tube of the viscometer. Determination of viscosity using ostwald viscometer with. These devices are also known as glass capillary viscometers or ostwald viscometers, named after wilhelm ostwald. Prepare 0%, 30%, 50%, 70%, 90% and 100% solution of glycerin in pure water. Viscometer, instrument for measuring the viscosity resistance to internal flow of a fluid. For more accurate measurements it is held in a controlled temperature bath. Ostwalds fame grew and he became professor at leipzig, germany. Information from its description page there is shown below. Group i 1 to find out type of alkalinity and estimate alkalinity present in the given water sample. D bottle known as pyknometer also, stand, beaker, unknown liquid, distilled water. Method a using ostwald type viscometer apparatus the apparatus consists of a glass utube viscometer see fig.
Insert the viscometer into a holder and place in constant temperature bath. When you enter the lab, switch on the exhaust fan and make sure that all the chemicals and reagents required for the experiment are available. Borosilicate glass ostwald oil viscometer, mechanics system 2 physics kit, thermocap plus capillary viscometer baths, made. Both are ushaped pieces of glassware with a reservoir on one side and a measuring bulb with a capillary on the other. The device utilizes direct or reverse flow of the test fluid through a ushaped tube to measure the fluids viscosity. We will, therefore, measure relative viscosity by using reference fluids with known viscosities. Turn the viscometer to normal position and wipe tube a clean.
Calculation of viscometer constants for cannonfenske. This cap is designed to protect the viscometer spindle coupling nut during shipment. Determination of viscosity by using ostwaldtype, suspended. Stokes law can be used to calculate the viscosity of the fluid.
Viscometers are instruments that can either apply a force and measure a speed, or apply a speed and measure a force, to or from a simple geometry. Poiseuilles law demonstrates that the laminar flow of a liquid through a small tube is proportional to the fourth power of the tubes radius, which is employed in the first method. The experimental determination of absolute viscosity is a difficult task. In one arm of the u is a vertical section of precise. Viscosity measurement using ostwalds viscometer amrita. A liquid is introduced into the reservoir then sucked through the capillary and measuring bulb.
The only precise instrument available was wilhelm ostwalds device in which a liquid was timed as it flowed through a capillary. For liquids with viscosities which vary with flow conditions, an instrument called a rheometer is used. The ubbelohde viscometer is closely related to the ostwald viscometer. To do this, use the adjustment screws of the support base and control the adjustment with the help of the spirit level on the viscometer. Temperature control is realized via liquid bath thermostat, while an operator manually performs measurement and cleaning.
Each virtual experiment includes a corresponding theoretical section. In one arm, the bulb a is connected with a fine capillary. Difference between ostwald and ubbelohde viscometers. Ostwald viscometers measure the viscosity of a fluid with a known density. In the viscometer a sample of liquid was charged from tube 1 to bulb c, so that level in the arm stands at the mark. For the most viscous glops, he used carl englers viscometer. Buy utube viscometerstubes, type of modified ostwald viscometers from pslrheotek. Viscosity of newtonian and nonnewtonian liquids rotary. Liquid viscosity measurement using capillary tube viscometer, cone and plate type. Experiment 3 experiment no 3 measurement of viscosity of. In one version, the time taken for a given volume of fluid to flow through an opening is recorded. Falling sphere viscometer the falling ball viscometer is based on stokes law.
A viscometer also called viscosimeter is an instrument used to measure the viscosity of a fluid. In the capillary tube viscometer, the pressure needed to force the fluid to flow at a specified rate. Thus, by knowing m, g, h, t, r, n1 andn2 from the experiment the mass moment of inertia i. The ostwald viscometer the ostwald viscometer fulfils these conditions. The hoeppler principle fritz hoppler, 1897 1955, german chemist, who designed this fallingball viscometer in 1933 7 conforms to din 53015 and iso 12058. Scope this method describes a procedure for determining the viscosity of 0.
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