16-05-2019 | | By Nnamdi Anyadike
The use of inductive proximity sensors is increasing globally, on the back of industrial applications such as: the search coil magnetometer that is used in electromagnetic waves measurement; metal detectors; traffic lights; car washes; and a host of other automated industrial processes. An inductive proximity sensor is basically a non-contact electronic proximity sensor that is used for the positioning and detection of metal objects. Because the sensor does not require physical contact it is particularly useful for those applications where access presents a challenge, such as in dirty or oily environments.
Sensors use the principle of electromagnetic induction to detect or measure objects. When a current flows through it an inductor develops a magnetic field. One form of inductive sensor drives a coil with an oscillator. The coil may have a ferromagnetic core to make the magnetic field more intense and to increase the sensitivity of the device. Another form of inductive sensor uses one coil to produce a changing magnetic field, and a second coil to sense the changes in the magnetic field produced by an object.
Key manufacturers in the inductive proximity sensors market include: Honeywell, OMRON, Panasonic, Pepperl+Fuchs, Rockwell Automation, Truck Inc., IFM Electronic, Fargo Controls, Broadcom and Eaton.
In April, Pepperl+Fuchs GmbH one of the world's leading companies for industrial sensors and explosion protection and the inventor of the inductive proximity switch launched a new inductive safety sensor portfolio. The new ‘safety’ sensor family comprises four cylindrical and parallel piped series with a cable and plug connection. Applications include the safeguarding of machines and plant components as well as secure position detection. The new portfolio also includes inductive sensors with an increased temperature range as well as increased EMC resistance and E1 approval for the use of mobile machines and vehicles in safety-critical areas.
The safety proximity switches do not require a special coded target and can thus be used with standard metal actuators. The sensors from Pepperl + Fuchs also have no blind zone and can therefore be mounted easily and without additional adjustment. For connection to a safety module or a corresponding controller, the sensors have standardized OSSD outputs (Output Signal Switching Device) for signal and diagnostics. The sensors’ components and solutions are also precisely tailored for use in potentially explosive areas.
Honeywell Safety and Productivity Solutions (S&PS) offers a range of environmentally sealed proximity sensors in a variety of technologies — including Eddy Current Killed Oscillator (ECKO) and Hall-effect. The company’s Web site explains, “Once a metallic object is detected in front of the sensing face, a signal is passed through the conditioning circuitry to give an output configured according to the sensor application.” In rail applications, the 2-wire dc inductive can make non-contact detection of rail wheel flanges at speeds up to 500 km/h. Added benefits include ease of installation, enhanced life and low ‘in track’ maintenance. It supports extended line-side transmission distances and facilitates use in wheel detection systems and fault diagnosis.
Panasonic offers a broad range of inductive proximity sensors for metallic sensing applications. Options include 2 and 3 wire DC types along with low cost, compact basic types. For high-performance sensing, Panasonic’s separate amplifier type can handle high-speed operations. The company’s GX-F12A-P rectangular-shaped oil resistant inductive proximity sensor, part of its GX-F/H series, is said by the company to have “the longest stable sensing range among the same level of rectangular inductive proximity sensors in the industry.” The sensors are easy to install and different frequency types are available. Panasonic also has a range of various cylindrical inductive proximity sensors as well as compact micro-size inductive proximity sensors.
The global inductive proximity sensors market can be said to be in excellent health. An expected CAGR of 9.4% over the next decade, according to a recent market intelligence report, will significantly increase its valuation from its estimated $1.3 billion this year. And although the use of inductive proximity sensor technology was practiced by large industries over a decade ago, improved technology has led to its widespread adoption by all tier companies to streamline operations, enhance industrial automation, and change the manufacturing landscape of companies. Applications are increasing in consumer electronics, industrial automation, automotive, aerospace and defence, pharmaceutical, and packaging, among others. The increase in the demand for smartphones and other mobile devices are important factors driving the inductive proximity sensors market. Another important growth factor is the increase in the number of vendors that is enabling industrial automation as well as growth in the demand for Industrial Internet of Things (IIoT).