What Is The Difference Between Inductive And Capacitive Sensors 7514m

What is the difference between inductive and capacitive sensors? Inductive sensors use a magnetic field to detect objects. Capacitive sensors use an electric field. In order to be sensed by an inductive sensor an object must be conductive. This limits suitable targets to metal objects (for the most part). In order to be sensed by a capacitive sensor the target doesn’t need to be conductive. A capacitive sensor will react to an object acting as a dielectric material as well as a conductive object. This makes metal and non-metal objects suitable targets. CAPACITIVE SENSOR-A capacitive sensor is a proximity sensor that detects nearby objects by their effect on the electrical field created by the sensor. ADVANTAGE -detect meta and nonmetal, liquids and

DISADVANTAGE - short (1inches or less) sensing distance

solids

varies widely according to material being

-can see through certain materials

sensed

(product boxes)

- very sensitive to environmental factors-

-solid-state, long life

humidity in coastal/water climates can

-many mounting configuration

affect sensing output -not at all selective for its target-control of what comes close to the sensor is

essential. How Inductive Proximity Sensor works The inductive proximity sensor can be used to detect metallic targets only. The main components of the inductive proximity sensor are coil, oscillator, detector and the output circuit. The coil generates the high frequency magnetic field in front of the face. When the metallic target comes in this magnetic field it absorbs some of the energy. Hence the oscillator field is affected. This is detected by the detector. if the oscillation amplitude reaches a certain threshold value the output switches. The inductive proximity sensor works better with ferromagnetic targets as they absorb more energy compare to non Ferromagnetic materials. Hence operating distance for sensor is more for Ferromagnetic targets. The advantages of inductive proximity sensors are 

They are very accurate compared to other technologies



Have high switching rate



Can work in harsh environmental conditions

The disadvantages of inductive proximity sensor are



It can detect only metallic targets



Operating range may be limited