What is mechanical gauge? | What are the types of mechanical gauges?

What is mechanical gauge? 

Whenever a very High Fluid Pressure is to be measured a Mechanical Gauge is best suited for the purpose. Mechanical Gauges is also used for the measurement of pressure is boilers or other pipes, where tube gauges cannot be conventionally used.

There are many Types Of Gauges available in the market. But the principle on which all these Gauges Work is almost the same. following three type of gauges are important from the subject point of view:-

What are the types of mechanical gauges?

1.  Bourdon's Tube Pressure Gauge
2.  Diaphragm Pressure Gauge
3.  Dead Weight Pressure Gauge

1.  Bourdon's Tube Pressure Gauge:

The pressure above or below the atmospheric pressure may be easily measured with the help of a bourdon's tube pressure gauge. A burdons tube pressure gauge in it is simplest form consists of an elliptical tube ABC. Bent into an Arc of a circle as shown in figure. This bent of tube is called burdon's tube.

When the gauge tube is connected to the fluid (whose pressure is required to be found out) at C the fluid under pressure flow into the tube. the Bourdon's Tube as a result of the increased pressure tend to strengthen itself.

Since the tube is encashed in a circular karva therefore it tend to become circular instead of straight. With the help of a simple pinion and sector attachment the elastic deformation of the bourdon's tube rotated the pointer. This pointer move over a calibrated scale which directly give the pressure as soon in figure.

Mechanical gauge diagram

2.  Diaphragm Pressure Gauge:

The pressure above or below the atmospheric pressure is also found out with the help of Diaphragm Pressure Gauge. Order from pressure gauge in its simplest form consists of the diaphragm ( instead of bourdon tube is article first of bourdon tube pressure gauge of this blog).

When the gauge is connected to the fluid (whose pressure is required to be found out) at C, the fruit under pressure causes from the formation of the Diaphragm. With the help of some pinion arrangement the elastic deformation of the diaphragm rotates the pointers. This pointer moves over a calibrated scale which directly give the pressure as shown in figure.

A diaphragm pressure gauge in generally used to measure relatively low pressure.

3.  Dead Weight Pressure Gauge:

It is the most accurate and pressure gauge which is generally used for the calibration of the other pressure gauge in a laboratory. Did weight pressure gauge in its simplest form consists of piston and cylinder of known area which is connected to a fluid through a tube as shown in figure.

The pressure of fluid in the pipe is calculated for from the relation,

p = weight / area of the piston

A pressure gauge to big calibrated is treated on the other end of the tube as shown in figure by changing the weight on the piston the pressure on the fluid is calculated and marked on the gas at the respective point indicated by the pointer.

 A small error due to frictional resistance to the motion of the piston come into play. but the same may be avoided by taking adequate precautions.




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