# What is the formula for calculating viscosity?

## What is the formula for calculating viscosity?

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 Saybolt Furol viscosity?

Saybolt Furol viscosity – the efflux time in seconds required for 60 milliliters of a petroleum product to flow through the calibrated orifice of a Saybolt Purol viscometer, under carefully controlled temperature, as prescribed by test method ASTM D 88.

How do you calculate centistokes?

It is also expressed in terms of centistokes (cSt or ctsk). 1 stokes = 100 centistokes = 1 cm2•s-1 = 0.0001 m2•s-1. 1 centistokes = 1 mm2•s-1 = 10-6m2•s-1.

### How does a Saybolt viscometer work?

A device used to measure the viscosity of a fluid. The saybolt viscometer controls the heat of the fluid and the viscosity is the time is takes the fluid to fill a 60cc container. The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress.

What are the different types of viscometer?

Three main types of viscometer are used: capillary tube (e.g., Ostwald), coaxial cylinder (e.g., Brookfield, Couette) and falling sphere (e.g., Hoeppler). For research, a sophisticated controlled stress rheometer such as a Carrimed or Bohlin may be used.

What is the formula and unit of viscosity?

Viscosity is a measure of a fluid’s resistance to flow. The SI unit of viscosity is poiseiulle (PI). Its other units are newton-second per square metre (N s m-2) or pascal-second (Pa s.) The dimensional formula of viscosity is [ML-1T-1].

## How do you measure viscosity manually?

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.

What is Saybolt number?

Highly refined petroleum products use the ASTM D 156 scale, also known as the Saybolt color scale which ranges from −16 (darkest) to +30 (lightest) (ASTM International 2003).

What is SSU Saybolt seconds universal?

Saybolt Universal Second (Often SUS or SSU) is a measure of kinematic viscosity used in classical mechanics . It is the time that 60 cm3 of oil takes to flow through a calibrated tube at a controlled temperature.

### What is the difference between Redwood viscometer and Saybolt viscometer?

Answer: A Redwood viscometer works on the same principle of Saybolt viscometer. Here, the stopper is replaced with an orifice and Redwood seconds is defined for collection of 50ml of liquid to flow out of orifice. In general, both the viscometers are used to compare the viscosities of different liquid.

What is a Saybolt viscometer?

Introduction Definition • A device used to measure the viscosity of a fluid. The saybolt viscometer controls the heat of the fluid and the viscosity is the time is takes the fluid to fill a container. • Efflux cup viscometers are most commonly used for fieldwork to measure the viscosity of oils, syrups, varnish, paints and Bitumen emulsions.

How do you calculate viscosity from Saybolt universal seconds?

Saybolt universal seconds (t) can be converted to kinematic viscosity (v) by the following equations: When t < 100 secs, v = 0.226t – 195/t Centistokes When t >100 secs, v = 0.220t – 135/t Centistokes The viscosity determinations should be conducted in a room free from drafts and rapid changes in temperature the highest degree of accuracy.

## What is specific viscosity in viscometer?

Saybolt Viscometer 1 The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. 2 The units of viscosity is poise and centipoise . 3 specific viscosity is the ratio of the viscosity of fluid to the viscosity of water at 20 degree Celsius.

Which viscometer is used to test petroleum products?

• The saybolt viscometer, one of the efflux cup viscometers is the standard instrument for testing petroleum products. • The testing procedure is quite similar to the capillary-tube viscometers 5.