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Inductive sensors use currents induced by magnetic fields to detect nearby metal objects. If there is a metal object near the changing magnetic field, current will flow in the object. This resulting current flow sets up a new magnetic field that opposes the original magnetic field.
Where are inductive sensors used?
Common applications of inductive sensors include metal detectors, traffic lights, car washes, and a host of automated industrial processes. Because the sensor does not require physical contact it is particularly useful for applications where access presents challenges or where dirt is prevalent.
What signal does an inductive sensor produce?
The inductive sensor, also known as magnetic pickup sensor, during the operational work, as result of inductive effect, in the sensor’s coil is producing the oscillating voltage, i.e. one kind of sinusoidal waveform signal (∼ AC voltage).
How do inductive sensors measure speed?
The sensor contains a coil that is wrapped around a magnet which cause a change in the magnetic current (flux) and the coil as the teeth of a gear pass the sensor. The moving gear creates a varying flux that induces a proportional voltage in the coil of which the frequency is related to the rotation speed.
What are the two types of inductive sensor?
Inductive Proximity Sensors are roughly classified into the following three types according to the operating principle: the high-frequency oscillation type using electromagnetic induction, the magnetic type using a magnet, and the capacitance type using the change in capacitance.
Can Inductive sensors detect copper?
An inductive sensor is an electronic device that can detect ferrous metal targets without physical contact. Inductive sensors will also detect non-ferrous metal targets like aluminum, brass, and copper. But using non-ferrous metal targets decreases an inductive sensor’s sensing range.
Can Inductive sensors detect aluminum?
These sensors have an equal range for aluminum and steel targets. In addition, these new inductive sensors have very long nonflush sensing ranges, allowing metals such as aluminum and stainless steel to be sensed at distances previously not possible.
What is the difference between a Hall sensor and a inductive sensor?
Hall effect sensors respond to static (non-changing) magnetic fields. This is a key difference from inductive sensors, which respond only to changes in fields.
What is the sensing distance of an inductive sensor?
Inductive proximity sensors enable the detection, without contact, of metal objects at distances of up to 60 mm.
How do you test an inductive sensor?
Unplug the sensor and check that the electrical resistance of the inductive coil is roughly between 500 ohms and 1.500 ohms. If the reading value is drastically different, including zero or infinite, replace the sensor.
Which sensor is used for speed?
Different Types of Speed Sensors Monopolar inductive sensors are inductive or magnetic sensors that measure wheel speeds without contact. They produce a so-called alternating voltage with an amplitude that can vary according to the speed of rotation, the shape of the prong, the materials used or the size of the gap.
What are inductive proximity sensors made of?
Inductive sensor housing is typically nickel-plated brass, stainless steel, or PBT plastic.
How does a two wire proximity sensor work?
The output operation is along the two power wires in the form of a voltage drop, thus making the sensor free to work with either polarity on the common. Because of this, you can use the 2-wire sensor to replace both the NPN and PNP 3-wire models, depending on the way you wire it up.
What is PNP and NPN sensor?
PNP sensors produce a positive output to your industrial controls input, while NPN sensors produce a negative signal during an “on” state. NPN, or “sinking” output sensors, work in the opposite way, sinking ground voltage to an input when it’s on.
Do inductive sensors work on stainless steel?
Inductive sensors are designed for the detection of metal targets at close range and are a popular choice for use as proximity switches in factory automation applications. Carbon steel is the typical target material for these sensors, but in some industries, stainless steel is more common.
Can an inductive sensor detect gold?
For detection of unique metal like gold, titanium, alloys, and others, the reduction factor 1 sensors should be able to do the job with consistent results for all metals. If a standard inductive sensor is chosen there might be a reduction factor involved depending on the metal type.
How does inductive proximity sensor detect metal?
Inductive sensors are noncontact. The sensors detect metal objects located in their measurement field. They use the interaction of the metal object as an electrical conductor with the emitted magnetic alternating field of the sensor to do so.
What is the difference between capacitive and inductive sensors?
Inductive sensors detect the proximity of metal targets to an inductive coil sensor, whereas capacitive sensors detect the change in capacitance between a sensor and electrode.
Which sensor is used to detect metal?
Detecting metal only Inductive proximity sensors can only detect metal targets. They do not detect non-metal targets such as plastic, wood, paper, and ceramic. Unlike photoelectric sensors, this allows a inductive proximity sensors to detect a metal object through opaque plastic.
What is the output of proximity sensor?
Proximity Sensors use semiconductor outputs, so there are no contacts to affect the service life. 3. Unlike optical detection methods, Proximity Sensors are suitable for use in locations where water or oil is used. Detection takes place with almost no effect from dirt, oil, or water on the object being detected.
What is magnetic pickup sensor?
Magnetic pickup (mpu) speed sensors convert the mechanical motion of an engine’s flywheel to an AC voltage without external power. It transmits a signal each time a flywheel gear tooth passes near the center pole piece to measure engine RPM.
How do magnetic proximity sensors work?
Magnetic proximity sensors are actuated by the presence of a permanent magnet. The presences of a magnetic field makes the thin plates flex and touch each other causing an electrical contact. The plate’s surface has been treated with a special material par-ticularly suitable for low current or high inductive circuits.
What changes the state of a 2 wire proximity switch?
This eddy current extracts energy from the LIC resonant circuit in the switch, and produces a reduction in the oscillation amplitude. This reduction in the amplitude is converted by the associated electronic circuitry into a clear electronic signal, and changes the state of the switch.
