Measurment of presuure, Manometer, Mechanical Gauge, Piezometer, Simple Manometer, Differential Manometer,

 

Measurment of pressure:-

The pressure of fluid is measured by ther following devices:-

1. Manometer

2. Mechanical gauge

1. Manometer:-

                             It is defined as the device's used for measuring the pressure at a point in a fluid by balancing the column of fluid by ther same or other column of the fluid. 

They are classified as:-

a. Simple Manometer

b. Differential Manometer

2. Mechanical gauge:-

                                         Mechanical gauge are defined as the device used for measuring the pressure by balancing the fluid column by ther shoring or dead weight. 

                                           The commonly used mechanical pressure gauge are:-

a. Diaphragm pressure gauge

b. Bourdon pressure gauge

c. Dead weight pressure gauge

d. Belows pressure gauge. 

Simple Manometer:-

Simple Manometer:-

                                       A simple manometer consists of a glass tube having one of its end connected to the point where is to be measured and other end remains open to atmosphere.

Ø  Common types of simple manometer are :-

         i.            Piezometer

       ii.            U-tube Manometer

      iii.            Single column manometer

1.       Piezometer :-

                               It is the simplest form of manometer used for measuring gauge pressure. One end of this manometer is connected to the point where pressure is to be measured and other end is open to the atmosphere.

·         The size of liquid give the pressure head of that point.

Pa = ρgh

 

2.       U-tube Manometer :-

                                             It consist of a glass tube bent in u-shape one end of which is connected to a point is which pressure is to be measured and other end remains open to the atmosphere.

·         The tube generally contains mercury or any other liquid whose specific gravity is greater than the specific gravity of liquid whose pressure is to be measured.

a.       For Gauge pressure :-

                                              Let B be the point where pressure to be measured.

The datum line A-A.

 

Let,

_{h1 =} height of light liquid above the datum line

_{h2 =}  height of heavy liquid above the datum line

_{S1 = specific gravity of light liquid}

_{S2 = specific gravity of heavy liquid}

_{ρ1 = density of light liquid}

_{ρ2 = density of heavy liquid.}