this is a slide based on proximity sensors, its types,and its application. A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal. The object being sensed is often referred to as the proximity sensor's target. Different proximity sensor targets demand different sensors. For example, a capacitive proximity sensor or photoelectric sensor might be suitable for a plastic target; an inductive proximity sensor always requires a metal target.[citation needed] Proximity sensors can have a high reliability and long functional life because of the absence of mechanical parts and lack of physical contact between the sensor and the sensed object. Proximity sensors are also used in machine vibration monitoring to measure the variation in distance between a shaft and its support bearing. This is common in large steam turbines, compressors, and motors that use sleeve-type bearings. Proximity sensors are commonly used on mobile devices. When the target is within nominal range, the device lock screen user interface will appear, thus emerging from what is known as sleep mode. Once the device has awoken from sleep mode, if the proximity sensor's target is still for an extended period of time, the sensor will then ignore it, and the device will eventually revert into sleep mode. For example, during a telephone call, proximity sensors play a role in detecting (and skipping) accidental touchscreen taps when mobiles are held to the ear.[1] Proximity sensors can be used to recognise air gestures and hover-manipulations. An array of proximity sensing elements can replace vision-camera or depth camera based solutions for the hand gesture detection.

1. PROXIMITY SENSORS
SUBMITTED BY-
SHUDHANSHU MALL
ROLL NUMBER-1813310219
BRANCH-CSE
COLLEGE NAME-NOIDA
INSTITUTE OF ENGINEERING
AND TECHNOLOGY SUBMITTED TO-
LAKSHMAN SINGH

2. TABLE OF CONTENT
 INTRODUCTION
 TYPES OF PROXIMITY SENSOR
 CONSTRUCTION
 WORKING
 APPLICATIONS
 ADVANTAGE
 DISADVANTAGE
 CONCLUSION
 REFRENCES

3. WHAT IS A PROXIMITY SENSOR ?
 A Proximity Sensor Detects An Object When
The Object Approaches Within The
Detection Range And Boundary Of The
Sensor.
 Proximity Sensor Includes All The Sensor
That Perform Non Contact Detection In
Comparison To Sensors Such As Limit Switch
, That Detect The Object By Physically
Contacting Them.

4. TYPES OF PROXIMITY SENSORS
 INDUCTIVE PROXIMITY SENSOR
 CAPACITIVE PROXIMITY SENSOR
 ULTRASONIC PROXIMITY SENSOR
 OPTICAL PROXIMITY SENSOR

5. INDUCTIVE PROXIMITY SENSOR
 An Inductive proximity sensor is an
electronic proximity sensor , which detect
metallic object without touching them.
 Their operating principle is based on a coil
and high frequency oscillator that creates a
field in the close surrounding of the sensing
surface .
 The operating distance of the sensor
depends on the coil’s size as well as the
target’s shape, size and material

6. CONSTRUCTION AND WORKING
 The Main Components Of The Inductive Proximity
Sensor Are. Coil, Oscillator, Detector And The
Output Circuit
 The Operating Distance Of The Sensor Depends On
The Actuator's Shape And Size And Is Strictly
Linked To The Nature Of The Material
 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

7. CONT…
 Hence the oscillator field is affected. The
rise or fall of such oscillation is identified
by a threshold circuit..that changes the
output of the sensor.

8. ADVANTAGES
 They are very accurate compared to other
technologies.
 Have high switching rate.
 Can work in harsh environmental
conditions.

9. DISADVANTAGES
 It can detect only metallic target.
 Operating range may be limited.

10. APPLICATIONS
 Common applications of inductive sensors
include metal detectors, car washes, and a
host of automated industrial process .
Because the sensor does not require
physical contact it is particularly useful for
applications where access presents
challenges or where dirt is prevalent . The
sensing range is rarely greater than 6 cm,
however, and it has no directionality.

11. Capacitive proximity sensors
 Capacitive Sensor Are Used For Non Contact
Detection Of Metallic Object And Non
Metallic Object(liquid, Plastic, Wooden
Material Etc.)
 Capacitive Proximity Sensors Use The
Variation Of Capacitance Between The
Sensor And Object Being Detected.
 Capacitance Methods Are Very Sensitive ,
Distance Down To One Micro Inch Can Be
Measured.

12. Construction and working
 The Main Components Of The Capacitive
Proximity Sensor Are Plate, Oscillator,
Threshold Detector And The Output Circuit.
 The Plate Inside The Sensor Acts As One
Plate Of The Capacitor And The Target Acts
As Another Plate And The Air Acts As The
Dielectric Between The Plates.
 The Capacitive Sensor Can Detect Any
Targets Whose Dielectric Constant Is More
Than Air

13. CONT…
 As the object comes close to the plate of the
capacitor the capacitance increases and as the
object moves away the capacitance decreases
 An electronic circuit inside the sensor begins to
oscillate. The rise or the fall of such oscillation is
identified by a threshold circuit and based on that
output switches.

14. OPTICAL SENSORS
 The Proximity Of The Object Is Detected By
The Action Of The Travelling Light Move.
 These Sensors Use Light Sensitive Elements
To Detect Objects And Are Made Up Of An
Transmitter (Light Source) And A Receiver
 The Object Within The Range Of The Sensor
Can Detect The Presence.

15. CONT…
 The Light Emitted By The Transmitter Focuses On
The Object Which Reflects To Be Received By The
Receiver Photo Diode.
 The Reflected Waves Travel Back And Received By
The Solid State Photo Diode, Through The
Receiver Lens.

16. ULTRASONIC SENSORS
 Ultrasonic Sensor Are Some Type Used In Place Of
Optical Sensors . Instead Of Using An Light Beam ,
A High Frequency Sound Wave Is Used.
 This Sound Wave Is Above Normal Hearing
Frequencies And Are Called Ultrasonic
Frequencies Around 40 KHz Are Common.
 The Ultrasonic Sensor Can Measure Distances In
Centimeters And Inches. It Provides Good
Readings In Sensing Large-sized Objects With Hard
Surfaces.

17. ULTRASONIC WORKING
 The ultrasonic sensor sends out sound and
receives it back using the receiver. Together, the
ultrasonic sensor's sender and receiver look like a
pair of eyes, but it is not a sight sensor. Instead,
those "eyes" are really more like a speaker and a
microphone (a sound sensor).

19. CONT…
 The Emitter And Detector Are 2 Separate
Units. The Emitter Emits The Light Which Is
Detected By The Detector. A Target Is
Detected When It Passes In-between The
Emitter And Detector.

20. CONCLUSION
 The global market for these proximity sensors is
expected to grow at a steady rate. Major
industries using proximity sensors are machine
tools, woodworking machines, packaging
machines and other types of machinery.
 Further applications of are automatic door units
such as garage doors or doors inside buildings,
elevator doors or doors inside railway coaches.
 The building and automotive sector are further
industries using high volumes of proximity
sensors.

21. PROXIMITY SENSOR IN SMARTPHONES
 The proximity sensor is common on
most smart- phones, the ones that
have a touch screen. This is because
the primary function of a proximity
sensor is to disable accidental touch
events. The most common scenario
being- The ear coming in contact with
the screen and generating touch
events, while on a call. If a proximity
sensor close to the speaker, then it will
detect any object in the vicinity of the
speaker. If any object is present (ex.
user's ear), then the touch events can
be assumed to be accidental &
ignored.