Infrared proximity sensor.

Proximity sensorFrom Wikipedia, the free encyclopedia

A proximity sensor is a sensor able to detect the presence of nearby objectswithout any physical contact.

A proximity sensor often emits an electromagnetic field or a beam ofelectromagnetic radiation (infrared, for instance), and looks for changes in thefield or return signal. The object being sensed is often referred to as the proximitysensor's target. Different proximity sensor targets demand different sensors. Forexample, a capacitive photoelectric sensor might be suitable for a plastic target;an inductive proximity sensor always requires a metal target.

The maximum distance that this sensor can detect is defined "nominal range". Some sensors have adjustments of the nominalrange or means to report a graduated detection distance.

Proximity sensors can have a high reliability and long functional life because of the absence of mechanical parts and lack ofphysical contact between sensor and the sensed object.

Proximity sensors are commonly used on smartphones to detect (and skip) accidental touchscreen taps when held to the ear

during a call.[1] They are also used in machine vibration monitoring to measure the variation in distance between a shaft andits support bearing. This is common in large steam turbines, compressors, and motors that use sleeve-type bearings.

International Electrotechnical Commission (IEC) 60947-5-2 defines the technical details of proximity sensors.

A proximity sensor adjusted to a very short range is often used as a touch switch.

Contents

1 Types of sensors2 Applications

3 Manufacturers4 References

Types of sensors

CapacitiveCapacitive displacement sensorDoppler effect (sensor based on effect)Eddy-current

InductiveLaser rangefinderMagnetic, including Magnetic proximity fusePassive optical (such as charge-coupled devices)Passive thermal infraredPhotocell (reflective)Radar

Reflection of ionising radiationSonar (typically active or passive)Ultrasonic sensor (sonar which runs in air)

Applications

Parking sensors, systems mounted on car bumpers that sense distance to nearby cars for parkingGround proximity warning system for aviation safety

Vibration measurements of rotating shafts in machinery [2]

Top dead centre (TDC)/camshaft sensor in reciprocating engines.Sheet break sensing in paper machine.Anti-aircraft warfare

Roller coastersConveyor systems

Beverage and food can making lines[3]

Mobile devices

Touch screens that come in close proximity to the face[1]

Attenuating radio power in close proximity to the body, in order to reduce radiation exposure[4]

Manufacturers

Autonics

OmronContrinex (http://www.contrinex.com/)di-soric (http://www.di-soric.com/)M.D. Micro Detectorsc3controlsPepperl+FuchsTurckRockwell AutomationEatonSick AGschneider ElectricProtocontrol instrumentsBanner

Bently NevadaSenstronicS K INTERNATIONAL - Proximity housing TubeProxel (http://www.proxel.com/)

References

http://www.sensors-transducers.machinedesign.com/guiEdits/Content/bdeee4/bdeee4_7.aspx

1. ^a b "Proximity sensor on Android smartphones" (http://thecodeartist.blogspot.com/2011/01/proximity-sensor-on-android-gingerbread.html). TheCodeArtist.

2. ^ Proximity Probes for industrial machinery vibration monitoring (http://www.ge-energy.com/prod_serv/products/oc/en/bently_nevada/proxprobes.htm)

3. ^ [1] (http://www.sencon.com/en/controls/can_line_sensors.php)

4. ^ Can a $100 iPad Case Improve 3G Data Power? Lab Test! (http://www.wired.com/gadgetlab/2011/12/pong-ipad-case-investigation/all)

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This page was last modified on 12 March 2014 at 10:12.

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