Inductive Transducer working and its application

By | May 15, 2020
inductive transducer working

The inductive transducer is used for the conversion of physical quantities into proportional electrical quantities such as in voltage or electric current. It plays an important role in the instrumentation system. It can measure physical quantities like displacement, temperature, motion, level, pressure, etc. The output which is obtained from the inductive transducer is in the electric form and its equivalent to the measured quantity. There are numerous types of transducer but in this, we will discuss inductive transducer only.

inductive transducer
Inductive transducer

What is Inductive transducer?

It is an electrical device used to convert physical motion into modifying inductance within. It is a self-generating type. Like it uses the principle of fundamental electric generator which means when a motion among a conductor as well as magnetic field induces a voltage within the conductor.

Self-inductance change:

It can be derived by


N= no. Of twists of coil

R= magnetic circuit reluctance


It primarily consists of the two-part of the coil, the first one is the movable magnetic core, the element that senses pressure. Not only this has the inductance of the coil changed as the AC voltage is applied to that. Moreover, there is a direct relationship with the inductance increase and the current decrease with the help of the coil. 


  • If there is a significant change in the quantity to be measured, then there is a significant change in the inductance.
  • The electromagnetic induction’s principle is applicable here, which is primarily used to measure or to detect the things.
  • The foremost fundamentals are the Famous law of Faraday
  • The principle of a fundamental electrical generator is applicable here. 


A magnetic field develops when a current is flowing through the active inductive transducer then instantly the current flow by the circuit that contains an effective inductor when the magnetic field changes through it. This effect is primarily used to indicate all the metallic jobs that usually associates with the field of the magnetic. 

However, the objects that are non-metallic like liquid or some different type’s dirt that won’t react with the field of the magnetic, this is the reason that the inductive sensor could effectively perform in any of the dirt conditions.

It works on two main functions:

  • Simple inductance

A single simple coil that is used as a transducer can be termed as the mechanical element whose displacement has to be evaluated, after that it will change the path of the flux permanence that is originated from the circuit. The final equivalent output is the modified version of the inductance circuit. Moreover, the output of the circuit can be adjusted corresponding to the value of the input. Hence this is the foremost reason that this value could be calculated. 

  • Two-coil mutual inductance

This is the second most fundamental and the different types of coils that are arranged in it. With the help of the external source of power, this primary coil will be generated. However, the focused output could be attained. Moreover, the input of the mechanical and the output are proportional to each other.

inductive transducer working


  • It is used for measuring the displacement, for which we use one of its types known as Linear Variable Differential Transformer (LVDT) to measure displacement in terms of the voltage difference between two secondary voltage.
  • It also used to detect the motion of the equipment, for which we the device we use known as a proximity sensor. It also measures position, touchpads.
  • It is used for the detection of metals, to find out the missing parts otherwise count the objects.


  • It will reduce load effects.
  • Higher the responsivity of transducers.
  • Strong against ecological quantities.


  • Due to the side effects, the operating range will be reduced.
  • Sensitive to the magnetic field.
  • The working temperature should lie under the cutie temperature.

Industrial Application of inductive Transducer

In industries, this device is used as a traffic light sensor.  It is also used as a metal detector. As the device is able to detect metal under the ground.  They are very useful in industries as this device as a proximity sensor is able to detect the presence and absence of an object other than its position. 

So, in this, we have discussed the inductive transducer and its applications. We go through its structure, the principle of working, where it applies, its advantages and disadvantages of uses and its working phenomenon. As we know any electronic device has some good as well as a bad impact also but besides this, it has numerous applications which are helpful for us in any sort of way. In a modern era, this device is helpful in maintaining the motion, metals, temperature, and pressure of the object by detecting them with the help of a magnetic field. It has two coils one is simple and the other one is a mutual two coil. Both have different working phenomenon and has different techniques to be work on.

Image credit goes to Bright Hub Engineering

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