Electrical transducer for displacement measurement

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basic three passive components Resistance Inductance and Capacitance can be used to measure the displacement 

Resistive transducer: potentiometer

The potentiometer  can be used to measure the displacement. It has two fixed  and one movable contact (wiper).

By using a potentiometer we can measure translational displacement, rotational displacement and helical displacement.


Construction

potentiometers are generally constructed in three form single slide wire, wirewound and sediment.

Characteristic

while choosing a potentiometer for application it is necessary to consider the following

Loading effects
Power rating
Linearity
Sensitivity


Advantages


(1) Inexpensive and simple to setup

 (2)Rather large displacement can be measured

(3)Sufficient output to drive control circuits

(4)Fresponse and resolution limited photo wirewound but unlimited for others

Disadvantages


(1) Mechanical loading woing to viper friction

(2)Electrical noise from the sliding contact

(3)wear and misalignment owing to fiction

(4 ) Quick manipulationg generate heats and associated problems

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