What is the principle of viscometer?

What is the principle of viscometer?

These viscometers use the principle of ‘rotational viscometry’, i.e. their measurement of product viscosity is based upon immersing a specifically selected spindle within a sample of the product followed by measurement of the torque required to rotate the spindle at a set speed whilst immersed within the product sample …

Why should the viscometer be dried before the measurements are done?

Drying the viscometer after cleaning Highly volatile solvents are recommended for cleaning since any remaining solvent will evaporate quickly after the sample has been flushed from the viscometer.

Can we reverse the bulbs in viscometer?

U-tube viscometers In one arm of the U is a vertical section of precise narrow bore (the capillary). Above there is a bulb, with it is another bulb lower down on the other arm. Such viscometers can be classified as direct-flow or reverse-flow.

Which method is used for the determination of viscometer?

Capillary Viscometers Measuring viscosity via a capillary tube is one of the oldest methods of determining the kinematic viscosity of a sample, requiring prior knowledge of the density and volume of the sample of interest. This fluid is passed through a vertical U-tube of known dimensions and very small diameter.

What is the use of viscometer?

A viscometer is an instrument used to measure fluid viscosity and the flow properties of liquids. Let’s discuss the various styles of viscometers, their internal characteristics and factors that go into performing a precise and repeatable viscosity measurement.

Why is viscometer not rinsed with the given liquid or water?

Explanation: Highly viscous samples will not easily pour from the instrument nor do they respond well even under vacuum. The best approach is to lower the viscosity by heating the instrument in an open oven or with a stream of hot air.

How accurate is a viscometer?

The estimated accuracy in each case is about 0.1 percent. The two results differ by 0.5 percent. Such liquids normally have a very high tem- perature coefficient of viscosity, and problems of adequate temperature control alone make it difficult to attain better than one percent agreemen t.

What is Brookfield viscometer?

The Brookfield Dial Reading Viscometer measures fluid viscosity at given shear rates. The Viscometer is able to measure over a number of ranges since, for a given spring deflection, the actual viscosity is proportional to the spindle speed and is related to the spindle’s size and shape.

What are advantages for Ubbelohde viscometer?

A Ubbelohde type viscometer or suspended-level viscometer is a measuring instrument which uses a capillary based method of measuring viscosity. The advantage of this instrument is that the values obtained are independent of the concentration.

How does Redwood viscometer work?

The redwood viscometer consist of vertical cylindrical oil cup with an orifice in the centre of its base . A hook pointing upward serve as a guide mark for filling the oil . The cylindrical cup is surrounded by the water bath . The water bath maintain the temperature of the oil to be tested at constant temperature .

Why is viscometer calibrated regularly?

About Viscometer Calibration Viscometers measure the viscosity – or thickness – of liquids and are often used in scientific, manufacturing, food service, and other industries. However, uncalibrated viscometers can compromise the quality of processes and products and cost your business extra time and money.

How is the oscillating piston viscometer used in the laboratory?

The oscillating piston viscometer technology has been adapted for small sample viscosity and micro-sample viscosity testing in laboratory applications. It has also been adapted to measure high pressure viscosity and high temperature viscosity measurements in both laboratory and process environments.

Is it possible to use two timings in one viscometer?

The use of two timings in one viscometer in a single run is only possible if the sample being measured has Newtonian properties. Otherwise the change in driving head, which in turn changes the shear rate, will produce a different viscosity for the two bulbs.

Which is one flow condition does a viscometer measure?

Viscometers only measure under one flow condition. In general, either the fluid remains stationary and an object moves through it, or the object is stationary and the fluid moves past it. The drag caused by relative motion of the fluid and a surface is a measure of the viscosity.

What is the principle of the falling ball viscometer?

The Falling Ball Viscometer is based on the measuring principle by Höppler for simple but precise dynamic viscosity measurement of transparent Newtonian fluids. The basic concept is to measure the elapsed time required for the ball to fall under gravity through a sample-filled tube inclined at an angle*.