GOVERNMENT COLLEGE OF ENGINEERING &
TECHNOLOGY
Active Learning Assignment
Subject :- Mechatronics
Topic: INFRARED SENSOR
Prepared by : RAJVEER PARIHAR

TOPICS
▪ WHAT IS IR SENSOR
▪ IR SENSOR STRUCTURE
▪ PRINCIPLE OF OPERATION
▪ KEY ELEMENTS OF IR DETECTION SYSTEM
▪ IR SENSOR WORKING
▪ APPLICATION
▪ PROS AND CONS

WHAT IS IR SENSOR
• An infrared sensor is an electronic instrument which is used to sense certain
characteristics of its surrounding by either emitting and/or detecting motion.
• Infrared sensors are also capable of measuring the heat being emitted by an
object and detecting motion.
• Infrared waves are not visible to human eye. In the electromagnetic spectrum,
infrared radiations can be found between the visible and microwave regions.
• The Infrared waves typically have wavelengths range from 780nm to 1mm

IR SENSOR MODULES

IR SENSOR STRUCTURE

PRINCIPLE OF OPERATION
IR LED KEEPS TRANSMITTING INFRARED RAYS UP TO SOME RANGE.
WHEN SOME OBJECTS COMES IN THE IR RANGE THE IR WAVE HITS THE OBJECT
AND COMES BACK AT SOME ANGLE
THE PHOTODIODE NEXT TO IR LED DETECTS THE IR RAYS WHICH GOT
REFLECTED FROM THE OBJECT.
No object present- no IR
detected by sensor
Object present- reflected
IR light detected by sensor

KEY ELEMENTS OF IR DETECTION SYSTEM
► IR TRANSMITTER
IR transmitter acts as an open source for IR radiation.in
most cases infrared laser, LEDs of infrared wavelength
are used as sources
► TRANSMISSION MEDIUM
Transmission medium provides passage for radiation to
reach from IR transmitter to IR receiver. Vacuum,
atmosphere and optical fibers are used as medium
► IR RECIVER
Generally IR receiver are photo diode and photo
transistor. They are capable of detecting IR radiation

IR SENSOR WORKING

APPLICATION
► PROXIMITY SENSOR
► ITEM COUNTER
► BURGLAR ALARM
► RADIATION THERMOMRETER
► HUMAN BODY DETECTION
► GAS ANALYZERS
► NIGHT VISION GLASSES
► FLAME MONITORS

PROS AND CONS
ADVANTAGES:
► LOW POWER REQUIREMENT
► SIMPLE CIRCUITERRY
► DIRECTION BEAM
► HIGH NOISE IMMUNITY
DISADVANTAGES:
► LINE OF SIGHT REQUIREMENT
► BLOCKED BY COMMON OBJECTS
► SHORT RANGE
► EASILY AFFECTED BY PHYSICAL ENVIRONMENT

THANK
YOU