Inductive sensor: operating principle and device
The inductive sensor is verya widespread device that is part of the lower-end equipment in automated production management systems. The devices are widely used in machine building, textile, food and other industries.The most effective devices are used in machine tools as limit switches, as well as in automatic lines.
In this case, inductive sensors only react tometals, while remaining insensitive to other materials. This property allows increasing the protection of devices from interference by introducing into their sensitivity zone various lubricants, emulsions and other substances that will not cause a false alarm.
Objects affected by inductiveposition sensor, are various metal parts: cams, sliders, gear teeth. In many cases, a plate attached to the equipment parts can be used.
According to statistics, of all the position sensors used, inductive devices account for more than 90 percent.This can be explained by their excellent performance characteristics, low cost and at the same time high reliability, which can not be said for other devices.
Non-contact switch (inductive sensor)works according to the following principles. The generator included in the device produces an electromagnetic field that interacts with the object. The required duration of the control signal and hysteresis during switching is provided by the trigger. The amplifier allows you to increase the amplitude of the signal to the desired value.
Located in the sensor light indicatorprovides prompt tuning, monitoring of operability and shows the status of the circuit breaker. To protect against penetration into the device water and solid particles used compound. The body of the product allows you to mount an inductive proximity sensor and protect the device from mechanical influences. It is made of polyamide or brass, completing hardware components.
During the operation of the device when feedingvoltage generator coil creates an alternating magnetic field, which is located in front of the active surface of the switch. If the object hits the sensitivity zone, the quality of the circuit and the amplitude of the oscillations decrease. As a result, the trigger is triggered and the state of the breaker output changes.
Inductive sensor has some featuresapplication. It can recognize different groups of metals, due to the absence of wear and mechanical impact is a durable device. The devices are equipped with short-circuit and overload protection mechanisms.
They are resistant to high pressure, are admitted in different versions for use at high (up to 150 Co) and low (from -60 Cabout) temperatures. The inductive sensor is resistant to active chemical media, it can have an analog or discrete output to determine the position relative to the device of the target object.