Float Type Liquid Level Indicators Working Principle and Advantages and Disadvantages

The float-operated level indicator is used to measure the liquid level inside any tank. In this, the float is placed on the surface of the liquid and shows the changes in the level of the liquid. Whatever change happens inside the float is shown on a scale measured by a pointer. 

Float can be of many types. 

(i) Hollow metal sphere. 

(ii) Cylindrical-shaped floats. 

(iii) Disc shape floats.

Construction

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A float-type level indicator is shown in the figure. So that we can find out the level of water in any water tank. By this method, we can see the movement of float on the indicator with the help of a pulley by stainless steel wire.

The float is made of a material that does not corrode and is placed between the two surfaces in such a way that no fault can be caused by the change of water. With the help of this instrument, the surface from 158 mm to 60 feet can be measured.

Working Principle

Due to the hydraulic transmitting system in this, we can take the liquid level to the farthest place. It is made with the help of bellows in which there are two sender sides C and D and two receiving liquids A and B. Bellows B, C, and A, and D are hydraulically connected to each other by pipes filled with a bottom.

The float moves up or down according to the water level then its position is communicated by a lower arm to a pair of bellows A and B. When the level of the liquid rises, B presses and A expands due to which the liquid filled in the pipe flows from B to C and from D to A. The bellows are balanced in such a way that they are regenerated in the opposite direction on the sending edge. 

C and D are connected to a pointer so that the temperature of the liquid level has no effect on the measurement of this instrument. With this instrument, the surface of liquid up to 25 feet can be measured.

Advantages and Disadvantages

Float-type level indicators are an important tool for industrial measurement and control, providing accurate and reliable level readings. The advantages of float-type level indicators include their ability to measure a wide range of liquid levels, from low to high, with a single device.

Advantages

(i) With its help, we can also find out the level of the tank which is kept underground. 

(ii) It is a very cheap and reliable device. 

(iii) It can work at very high temperatures. 

(iv) In this we can use non-rusting metal.

Disadvantages

(i) Normally it works at normal pressure. 

(ii) This device has to be modified according to the design of the tank.