1. LEVEL MEASUREMENT
BY,
B.Raveender Singh

2. Level Measurement CONTENTS Classification of level system
Brief introduction to the methods
Level switches
Summary

3. Level Measurement Classification of Level Measurement Systems:
LEVEL SYSTEMS
THERMAL TYPES
MECHANICAL METHODS
ELECTRICAL TYPES

4. Level Measurement
Classification of Mechanical Level Measurement Systems:
MECHANICAL METHODS
FLOAT TYPE
GAUGE/SIGHT GLASS
HYDROSTATIC TYPE
DISPLACER TYPE

5. Level Measurement GAUGE GLASS Simplest of level indication
Direct level indication
For local display
Can also be used for closed/pressurized tanks

6. Level Measurement Float Type Level Measurement:
Used mainly for open tanks local level indication.
Float and tape method is widely used.
Spherical floats are preferred .
Magnetic bond type ball float .

7. Level Measurement Displacer Type : Principle of operation :
Works on Archimedes Principle of Buoyancy
It states that the resultant force of a fluid on
a body immersed in it acts vertically upwards,which
is equal to the weight of the liquid displaced.

8. Level Measurement Theory
Buoyancy Force F = (Vx * Ph*g) + (V-Vx )*PL *g
V – Displacer volume
Vx – Volume of medium displaced by displacer
Ph – Average density of heavier medium.
PL -- Average density of lighter medium.
Fg -- Displacer body weight. Vx V Fg F

9. Level Measurement Displacer Type : Commercially named as Level Trol.
Torque tube forms the main transducting element.
Torque developed is converted to standard signal and transmitted to control room.

10. Level Measurement Displacer Type :
Mainly used for remote level indication and control
Simple reliable and accurate.
Can be used for liquids which tends to solidify under atmospheric conditions.
Can be used at very high temperatures and pressures.

11. Level Measurement Hydrostatic Type :
Hydrostatic head is the force due to liquid weight above the reference line .It is exerted equally in all directions and independent of volume or shape of the vessel.
Pressure P = p g h
P – density h