Inductive Sensor – Working & Its Applications

• The inductive sensor is used to detect a metal object. It works on the principle of electromagnetic induction which inducts the magnetic field when current flow through it.
• Near the changing metallic field if there is an object then current flow in the object.

• The new magnetic field is generated and this new magnetic field opposes the original magnetic field.
• The inductive sensor also detects the nonferrous metal target, but it decreases the sensing range.
• Its sensing range is the distance from the sensor face to the distance of the sensor to detect a metal target and the sensing distance is 12mm.

• It works only if the object is steel and it has a significant amount of iron in it.

Working of Inductive Sensor

• It detects metal objects located in their measurement field.
• The interaction of the metal object as an electrical conductor with the emitted magnetic field of the sensor.
• In the electrical conductor, eddy currents are induced, which extract energy from the field and thus affect the level of the oscillation amplitude.

• The core of the inductive sensor is a coil, which allows the magnetic field to flow in a specific direction.
• The oscillator located back to the sensor uses an LC resonant circuit to generate a magnetic field, which flows from the sensing face of the sensor.
• Then eddy currents are induced in the metal object located in the measurement field.
• The oscillator changes the signal level. The change in signal level then switches the output stage in binary sensors via a Schmitt trigger.
• In measuring sensors, this change in signal level affects the analog output signal depending on the object distance.

Applications of Inductive Sensor

• It can be used to detect parts in place at workstations, conveyor stops, and robots.
• It is used to detect if an air cylinder is extended or retracted and if a pallet stop or chain transfer is raised or lowered.
• It is also used in traffic signals to control the intersection of the road.
• Inductive sensors can be used to tell the VFD (Variable frequency drive )when to slow down and stop.
• It is also used in Space magnetometers to investigate electromagnetic waves in space plasma as well as natural electromagnetic wave observations on Earth.