1. Group members K17CE10 K17CE49 K17CE12

2. Introduction Classification of pressure Pressure measurement instruments Mechanical gauges

3. pressure Force per unit area, exerted by a fluid on surface of container SI unit is Pascal or N/sq: m Static pressure(Constant pressure) Dynamic pressure(Varying pressure)

4. UNITS 1 atm=14.7 psi (Mean sea level =101.3kP =760mm =1013 mb 1Bar=100Pascle

5. Fluid measurement pressure There are three standards 1-Absolute zero/Perfect vacuum. -It is the reference point of measuring all types of pressure including GUAGE and ATMOSPHERIC pressure. P abs = P atmospheric + P guage -This pressure is of outer space. -Value of pressure above the absolute zero pressure called absolute pressure. 2-Atmospheric pressure. Pressure measured above the point of atmospheric pressure values called ATM pressure. -It is the pressure of our space surrounding earth. Atmospheric pressure=Absolute pressure-gauge pressure

6. -reference values are -101325N/m² -76cm -760mm -14.7psi -760torr --Gauge pressure/Vacuum pressure -Pressure measured below the point of atmospheric called gauge pressure. This pressure can be positive or negative pressure. Gauge pressure=Absolute pressure-atmospheric pressure

7. Reference lines

8. Manometers. Manometers are devices used for measuring pressure at a point in a fluid by balancing the column of fluid or another column of fluid. -glass tube. -Manometric fluid is filled. Fluid is of different densities in different types. -there are two types of manometer 1-Simple manometer This type of manometer is used for measuring pressure at a point. It is further classified into PEIZOMETER -it is the simplest form of manometer

9. - fluid used in instrument is that of vessel whose pressure is to be measured. - -it works only, when fluid pressure is greater than atm: pressure. - -Due to pressure difference the level of fluid id raised to certain height. - Demerits - It can only measure moderate and low valued pressures. - It can not measure gauge pressures. - Pressures lighter specific gravity fluids can’t be measured. - It can not measure high pressures.

11. -A well type shaped. -fluid used is of greater than density than the vessel fluid. -This measures very small values of pressure. -this is modified form of u tube meter. The reservoir used is 100 times greater in x- section as compared to tube in left limb of u tube meter. Very small change in reservoir’s liquid will indicate the change in pressure in other tube. Advantages. It can measure positive as well as negative values of pressure. Easy to install and use. It also measures the small values of pressure.

13. This is u shaped manometer. -Fluid in u tube is greater density that of vessel. -This can measure high values of pressure -Gauge pressures and atmospheric pressures can be measured. -Water and mercury can be used as manometric fluid because they will not stick to the surface of tube. Advantages This tube can measure +ve and and –ve values of pressure. -Vacuum pressure can be measured. -Easy to install and handle - As compared to peizometer it can measure high values of pressure

15. - This type of manometer is used for small values of pressure. - Fluid is used in manometer is of greater density than the vessel fluid. - it is more sensitive than the vertical single column manometer. - Due to inclination distance moved by heavy liquid is more in right hand limb. - It has same advantages that of VSCM.

17. DAFI : Manometer used to measure the difference in pressure between points in a pipe or in different pipes. Types of differential manometer 1-U tube manometer It is u shaped tube It contains the heavy liquid or fluid of greater density Two ends are connected to the pipes whose pressure is going to be measured. If These both end are at same level and contains same fluid than u tube manometer used is shown in figure Pressure in A head - pressure in B head= height attend by tube fluid(difference in densities of both fluids)

19. Differential u tube whose ends are not at same level and have different fluids in both ends It is used to measure pressure between different kind of fluids and which possess different densities.

20. It is type of differential u tube manometer Which is used as inverted u tube meter It is used for measuring pressure between two fluids.

21. These are used for measuring high pressure. These are also called elastic gauge - These instruments cover ranges from - 0……….. 0.5mb to 0……….7000bar - It indicates accuracy up to 0.1% - Types of mechanical gauges - 1-Bourden tube - 2-Diaphragm gauge - 3-vacuum gauge

22. Bourdon tubes are redially formed tubes with an oval cross section Pressure of media acts on inside of the tube.The end of the tube which is not fixed this movement being a measurement for the pressure. This movement is indicated by a printer. The circular shaped tubes, bent at an angle of 250◦ The bourdon tube are generally made of bronze or nickle steel.

24. Diaphragm is a elastic material which is displaces, when it is applied to it. This movement of diaphragm to rack and pinion.The latter is attached to the spindle of moving on a graduated dial, the dial can again be graduated in a suitable scale

26. The device for measuring pressure below atmospheric pressure in the receiver of an air pump, in steam condensers. Ionization gauges are useful for high vacuum measurement, where direct pressure is too low ton mechanically deflect a gauge