EI 336- Industrial Instrumentation -II
PREPARED BY: M.V. MINI
1) Define Viscosity.
It is a measure of fluidity of the system. Many fluids undergo continuous deformation with the application of shearing stress.
2) Define Newtonian fluids
If the force flow relation is linear then the fluid is Newtonian . 3) Define Non Newtonian fluids
If the force flow relation is non linear then the fluid is Newtonian . 4) Define Kinematic Viscosity.
Ratio of absolute viscosity to the density of the fluid.
V= µ cm2 /ς sec
5) Define Specific Viscosity.
Ratio of absolute viscosity of the fluid to the absolute viscosity of a standard fluid at the same temperature.
µs = µ / µh
6) Define Relative Viscosity.
Ratio of absolute viscosity of the fluid at a given temperature to the absolute viscosity of a standard fluid at 20°c.
7) Define Viscosity index
It is an empirical number that indicates the effect of change of temperature on viscosity if a fluid. 8) Define fluidity.
It is the reciprocal of viscosity. It is unit is 1/ poise.
9) Define Humidity.
It is basically moisture content in air or it is the quantity of water vapour retained by gas. 10) Define Absolute Humidity.
Weight of water vapour in unit wait of gas.
H=Wr / Wg
11) Define Specific Humidity.
It is weight of vapors in unit weight of mixture.
12) Define Relative Humidity.
This is the ratio of moisture content of gas to maximum moisture content of the gas at that temperature.
13) Define dew point.
This is the saturation temperature of the mixture at the corresponding vapour pressure. 14) Define various units of Humidity.
Vppm = parts per million / volume.
G/ kg = weight concentration
Relative humidity = in %
Dew point in °C.
15) Define Hygrometer.
Used to measure the moisture content in air. It also used to measure humidity. 16) What is the basic principle of Hygrometer.
It consist of mechanical device measuring the dimension change of humidity sensitive materials like animal hair, animal membrane , paper etc.
17) Define Moisture.
Defined as the amount of water absorbed by solids or liquids. 18) What are the various methods of measurement of moisture. Based on the weight of the particle
Based on the resistance, capacitance,
19) How will you find the % moisture present in the substances. % Mp = ( Wwet - Wdry ) / Wwet * 100
20) What are the different types of viscometer?
Say bolt viscometer
21) What is Psychrometer?
Psychrometer is a device that uses the bulb thermometers to measure humidity. It is also used in air conditioning systems for maintaining humidity.
22) What are the different types of hygrometer?
Wire electrode hygrometers
Electrolysis type hygrometers
23) Explain the principle of saybolt viscometer.
As the viscosity of the fluid varies , the flow rate and hence time taken to drain the fluid through the capillary tube varies. The time indicates the viscosity and is denoted by say bolt number. 24) What is meant by consistency?
General term for viscosity and more often used in connection with Non-Newtonian fluids. 25) Explain the principle of oscillating type consistency meters. When the inner cylinder is given an axial sinusoidal motion through a mechanical drive rod, the fluid in the annular space gets a shearing force and the motion in the inner cylinder well to transmitted the magnitude of this transmission will depend on the consistency of fluid.
26) What are the units of velocity?
Feet per second (fsp)
Feet per minute (fpm)
Meters per second (mps)
27) Define Bernoulli equation.
In a given flow system, there is a relationship between pressure, fluid velocity, and elevation at any two points .
28) define Reynolds number.
Combination of density, viscosity of the fluid to a dimension describing length and the average fluid velocity.