The Principle of all the Pressure Measuring Devices are almost same,but for our convenient sake,we may divide it into following two types.
In this post I will cover details about Tube Gauges.
Tube Gauges to measure Fluid Pressure.
The Device used to measuring Fluid Pressure,by the Gauges are,
Details about Piezometer Tube.
It is the simplest form of Manometer,used for measuring moderate pressure.It consist of a Tube,open at one end to the Atmosphere,in which,Liquid can rise freely without overflow,the Height,to which the Liquid rises up in the Tube,gives the Pressure Head directly.
To find out the Pressure of a Liquid flowing through pipe,a Piezometer Tube is connected to the pipe.The important care to be taken that the Tube should not project inside the pipe beyond the surface,all the burrs and roughness near the hole must be removed and the edge of the hole should be rounded off.
A Piezometer Tube is not suitable for measuring Negative Pressure because Air will enter in the pipe through the Tube.
Details about Manometers.
It is the improved form of a Piezometer Tube.With the help of Manometer,you can measure,High Pressure and Negative Pressure also.
Following are four important types of Manometers.
It is the slightly improved form of Piezometer Tube for measuring High as well as Negative Pressure of Liquid.It consist a tube bent in U-shape,one end of which is attached to the Gauge point and another is open to the Atmosphere.
Generally,Mercury which is 13.6 times heavier than Water is used as Liquid in Simple Manometer.Hence you can measure High Pressure also.
It is the modified form of Manometer,in which cross section area of Left Limb is 100 times larger than that of Right Limb.A Micromanometer,is used for measuring Low Pressure,where accuracy is much more important.
These Micromanometer is further divided into two types which are
A)Vertical Tube Micromanometer
B)Inclined Tube Micromanometer
The Inclined Tube Mocromanometer is more sensitive than that of Vertical Tube Micromanometer.
It is the Device used for measuring the difference of Pressures,between two points in a pipe or in two different pipes.
A Differential Manometer,in its simplest form,consists of a U-tube,containing heavy liquid ,whose two ends are connected to the points,whose difference of Pressure is required to be found out.
04)Inverted Differential Manometer:-
It is particular type of Differential Manometer,in which an inverted U-tube is used.It is used for measuring difference of Low Pressures,where accuracy is the prime consideration.
It consists of an Inverted U-Tube,containing a light Liquid whose two ends are connected to the point whose difference of Pressure is to be found out.