1. Pressure Measurements
Presented By:
Vinod Dahiya
Lecturer Mechanical Engg.
RGGP Narwana

2. Pressure Measurement

3. 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 = kpa)

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

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

6. 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

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

8. 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.

9. Inclined tube manometer

10. 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

11. Well type manometer
Well type manometer

12. Ring manometer

13. 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.

14. Bourdon tube pressure gauge

15. Advantages:- Disadvantages:- Hysteresis on cycling 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

16. Bellow pressure gauge
Bellow pressure gauge

17. Bellow differential pressure gauge

18. ….THANK YOU….