How do you calculate viscosity by Ostwald viscometer?
- Ostwald viscometer is used to determine viscosity of Newtonian fluid.
- η1 can be determine using following equation.
- η1=ʆ1t1/ ʆ2t2 X η2
- ʆ1=Density of unknown liquid.
- t1 =Time of flow of unknown liquid.
- ʆ2 =Density of standard liquid.
- t2 =Time of flow of standard liquid.
- η2=Viscosity of standard liquid.
How do you calculate experimental viscosity?
To measure viscosity, fill a graduated cylinder with the liquid to be measured and mark the liquid’s positions at the top and bottom of the cylinder. Drop a marble into the liquid and start a stopwatch, then record the time it takes for the ball to drop between the marks.
How do you find the viscosity of a viscometer?
in milligrams per cubic millimetre, obtained by multiplying its relative density ( ) by 0.9982, t = flow time, in seconds, of the liquid to be examined. The constant k is determined using a suitable viscometer calibration liquid. To calculate the kinematic viscosity (mm2·s− 1), use the following formula: v = kt.
What is Ostwald viscosity?
Ostwald viscometer, also known as U-tube viscometer or capillary viscometer is a device used to measure the viscosity of the liquid with a known density.
How do you calculate the viscosity of glycerol?
To convert νg to μg, the glycerol density, ρg (kg/m3), is computed as which gives the best fit of the measurements for T = 17−83 °C by Adamenko et al. The predicted dynamic viscosities using eqs 22 and 23 differ at most by 1.6%.
What is the formula of kinematic viscosity?
Kinematic Viscosity (cSt) = (0.22 × t) − (195/t).
Can you calculate viscosity from specific gravity?
The really important thing to keep in mind is that there is no correlation between viscosity and specific gravity.
How is viscometer torque calculated?
The viscous coefficient, k , is said to relate viscous torque to angular velocity in the following manner, τ=−kω. A new relationship can be studied by adding areas of resistance, or rigid flags, over which the viscous force is acting, to increase drag.
What is the coefficient of viscosity of glycerine?
The glycerin coefficient of viscosity is a constant value which is 0.95 Pa-sec in S.I unit and 9.5 Poise in CGS unit system. The coefficient of viscosity in liquid is independent of the type or chemical composition of the liquid. It depends on temperature of the fluid.
What is the viscosity of glycerol at 20 degrees?
|Structure and properties|
|Surface tension||63.4 mN/m at 20°C 58.6 mN/m at 90°C 51.9 mN/m at 150°C|
|Viscosity||1.412 Pa·s at 20°C|
How do you calculate kinematic and dynamic viscosity?
Density actually provides a way to convert between a kinematic and a dynamic viscosity measurement. The formula for the conversion is: Kinematic (cSt) x Density = Dynamic (cP)
How do you calculate dynamic viscosity?
Dynamic viscosity (sometimes referred to as Absolute viscosity) is obtained by dividing the Shear stress by the rate of shear strain.
What is Ostwald viscometer?
What is the percentage on viscometer?
Repeatability and precision. Brookfield viscometers have a guaranteed accuracy of + -1% relative to the full scale value of the moving / speed combination used. The repeatability of the measurement is given at + -0.2 %. The precision is therefore one graduation out of 100, including 1 % Full Scale Range FSR.
How do you calculate viscosity formula?
There are several formulas and equations to calculate viscosity, the most common of which is Viscosity = (2 x (ball density – liquid density) x g x a^2) ÷ (9 x v), where g = acceleration due to gravity = 9.8 m/s^2, a = radius of ball bearing, and v = velocity of ball bearing through liquid.
What is relation between viscosity and specific gravity?
Like specific gravity, viscosity can be altered by a change in temperature, but unlike specific gravity it can also be altered by agitation. The really important thing to keep in mind is that there is no correlation between viscosity and specific gravity. We measure specific gravity with a hydrometer.
What is the formula for viscosity of fluid?
Dynamic viscosity is related to kinematic viscosity by the equation μ = ρν where ρ is the density of the fluid. The unit of dynamic viscosity μ is centipoise. If fluid density ρ has the unit of g/cc, then kinematic viscosity ν has the unit of centistoke.
What is SL unit of Viscocity coefficient n?
SI unit: Ns. m. -2. CGS unit: poise.