How is viscometer constant calculated?
How is viscometer constant calculated?
The calibration constant for the viscometer at 100°C can now be calculated using the same equation. Viscometer No. (cP) multiply the kinematic viscosity in mm2 /s( cSt) by the density in grams per milliliter.
How does an Ubbelohde work?
An Ubbelohde type viscometer or suspended-level viscometer is a measuring instrument which uses a capillary based method of measuring viscosity. The liquid is allowed to travel back through the measuring bulb and the time it takes for the liquid to pass through two calibrated marks is a measure for viscosity.
How do you find the viscosity of a capillary viscometer?
To obtain kinematic viscosity (v = ny), multiply the measured flow time (tf) by the so-called capillary constant (KC). This constant needs to be determined for each capillary by calibrating the capillary, i.e. by measuring a reference liquid of known viscosity.
How do you calculate relative viscosity?
Dividing the viscosity of the polymer solution (η) by the viscosity of the pure solvent (ηο) gives the relative viscosity with the dimensionless unit. Equation 7: Relative viscosity is the viscosity of the polymer solution divided by the viscosity of pure solvent.
How does a capillary tube viscometer work?
More sophisticated capillary viscometers work by applying an external pressure to the fluid or by forcing the fluid at a predetermined flow rate and measuring the pressure drop.
How do you measure viscosity of oil using a viscometer?
The most common method of determining kinematic viscosity in the lab utilizes the capillary tube viscometer (Figure 1). In this method, the oil sample is placed into a glass capillary U-tube and the sample is drawn through the tube using suction until it reaches the start position indicated on the tube’s side.
How do you find the relative viscosity of water?
The relative viscosity is the ratio of the viscosity of the confined water to the viscosity of the bulk water, i.e., η r = η cnt/η bulk. Here, the viscosities of the bulk water at the three temperatures are 0.668 mPa s at 298 K, 0.426 mPa s at 325 K, and 0.307 mPa s at 350 K, respectively.
Who was the inventor of the Ubbelohde viscometer?
Dr. Leo Ubbelohde, the inventor of the Ubbelohde viscometer. An Ubbelohde type viscometer or suspended-level viscometer is a measuring instrument which uses a capillary based method of measuring viscosity.
How does The Ubbelohde measure viscosity of liquid?
The liquid is allowed to travel back through the measuring bulb and the time it takes for the liquid to pass through two calibrated marks is a measure for viscosity. The Ubbelohde device has a third arm extending from the end of the capillary and open to the atmosphere.
What kind of measuring instrument is the Ubbelohde?
An Ubbelohde type viscometer or suspended-level viscometer is a measuring instrument which uses a capillary based method of measuring viscosity. It is recommended for higher viscosity cellulosic polymer solutions.
What do you mean by experimental determination of viscosity?
Experimental determination of viscosity (viscometer) Viscometry is the experimental determination of the viscosity of liquids and gases with so-called viscometers. 1 Definition of viscosity (Newton’s law of fluid friction)