Manometers Pressure gauges

1. Pressure
Measurement

2. Pressure
• Pressure (P) expresses the magnitude of normal force(F) per unit area(A) applied
on the surface.
• SI units :- Pascal (N/m²)
• Other units:- bar(=10⁵ pa),atm (=101.3kpa),
• mm hg or ( torr = 0.133322kpa)

3. Pressure measurement instrument
 Manometer
• U tube manometer
• Single column/micro manometer
• Well type manometer
• Inclined tube manometer
• Ring type manometer
• Bourdon pressure gauge
• Bellow pressure gauge
• Bellow differential pressure gauge
 Pressure gauge

4. U-tube manometers
Just before connecting the U tube Just after connecting the U tube

5. • U-tube manometer is a simple manometric device used to measure pressure at a
point in a fluid.
• balancing the fluid column by the same or another column of fluid.
• in liquid column used manometric liquids are mercury, water or alcohol.
• Some of the important and desirable properties of the manometric liquids are:
• High chemical stability
• Low viscosity
• Low coefficient of thermal expansion
• Low volatility
• Low vapour pressure

6. Single Column/Micro-manometer
Before connecting micro-manometer After connecting micro-manometer

7. • Single column/micro-manometers are just similar to the U-tube manometer, only
with a difference of having a small reservoir in the tube.
• Micro-manometer has a glass tube bent in “U” shape or inclined and has a small
reservoir in the tube, having some amount of same or other type of fluid called
manometric fluid.

8. Inclined tube manometer

9. • An incline manometer is a manometer that uses an incline to measure a small pressure
change. To calculate the pressure change for an incline tube manometer.
γ = Specific Weight
P = Pressure

10. Well type manometer
Well type manometer

11. Ring manometer

12. Bourdon tube pressure gauge
Principle:- The bourdon tube works on a simple principle that a bent tube will
change its shape .
As pressure is applied internally, the tube straightens and returns to its original
form when the pressure is released .
The tip of the tube moves with the internal pressure change and is easily converted
with a pointer onto a scale.

13. Bourdon tube pressure gauge

14. Advantages:-
Inexpensive
Wide operating range
Fast response
Good sensitivity
Direct pressure measurements
Disadvantages:-
Hysteresis on cycling
Sensitive to temperature variations
Limited life when subjected to shock and vibrations

15. Bellow pressure gauge
Bellow pressure gauge

16. Bellow differential pressure gauge
Bellow differential pressure gauge

17. ….THANK YOU….