02-04-2011, 10:23 AM
PRESENTED BY
GAURAV PURI
sensors.ppt (Size: 278 KB / Downloads: 594)
OPTICAL SENSORS AND THEIR APPLICATIONS
INTRODUCTION
NEW REVOLUTION OF OPTICAL FIBER SENSORS
IT IS A “SPIN-OFF” FROM OTHER OPTICAL TECHNOLOGIES
SEEING THE POTENTIAL IN SENSING APPLICATIONS – DEVELOPED AS ITS OWN FIELD
WHY OPTICAL SENSORS
ELECTROMAGNETIC IMMUNITY
ELECTRICAL ISOLATION
COMPACT AND LIGHT
BOTH POINT AND DISTRIBUTED CONFIGURATION
WIDE DYNAMIC RANGE
AMENABLE TO MULTIPLEXING
WORKING PRINCIPLE
SENSING DETAILS
EP(t)cos[ωt+θ(t)]
• INTENSITY BASED SENSORS – EP (t)
• FREQUENCY VARYING SENSORS - ωP(t)
• PHASE MODULATING SENSING- θ(t)
POLARIZATION MODULATING FIBER SENSING
CLASSIFICATION
EXTRINSIC SENSORS
CLASSIFICATION (contd.)
INTRINSIC SENSORS
COMPARISON OF THE TWO TYPES
SENSOR TYPES
CHEMICAL SENSORS
REMOTE SPECTROSCOPY
GROUNDWATER AND SOIL CONTAMINATION
MAJOR PLAYERS IN CHEMICAL SENSORS
1) PHARMACIA BIOTECH (SWEDEN)
2) FIBERCHEM
3) THE QUANTUM GROUP
TEMPERATURE SENSORS
LARGEST COMMERCIALLY AVAILABLE SENSORS
RANGE -40 deg C TO 1000 deg C
US-SMALL COMPANIES, JAPAN- HITACHI n SUMITOMO
STRAIN SENSORS
FIBER BRAGG GRATINGS (FBG) TECHNOLOGY
SENSES AS LITTLE AS 9 MICROSTRAIN
NRL and UNITED TECHNOLOGY RESEARCH
BIOMEDICAL SENSORS
SPECTROSCOPIC BIOMEDICAL SENSORS
CO 2, O 2 and pH CAN BE MEASURED SIMULTANEOUSLY
FLOW MONITORING BY LASER DOPPLERIMETRY
FIBERS – OPTHALMOLOGIC APPLICATION
ELECTRICAL AND MAGNETIC SENSORS
APPEALING- INHERENT DIELECTRIC NATURE
LESS SENSITIVE TO ELECTROMAGNETIC INTERFERENCE
SMALL SIZE AND SAFER
THEY ARE ALMOST ALWAYS HYBRID
ABB CORPORATION RESEARCH CENTER
ROTATION SENSOR
BASED ON THE SAGNAC EFFECT
TWO TYPES RING LASER GYROSCOPE (RLG) AND FIBER OPTIC GYROSCOPE (FOG)
US COMPANIES PURSUING HIGH PERFORMANCE FOG’s (HONEYWELL, LITTON, NORTHRUP, ALLIED SIGNAL etc.)
PRESSURE SENSORS
EARLIER BASED ON PIEZORESISTIVE TECHNIQUE
BASED ON MOVABLE DIAPHRAGM
HIGH PERFORMANCE- (POLARIZATION BASED SENSORS)
OPERATING PRESSURE RANGES FROM 0-70,000 torr
DISPLACEMENT AND POSITION SENSORS
ONE OF THE FIRST OPTOELECTRONIC SENSORS TO BE DEVELOPED.
SIMPLE SENSORS RELY ON THE CHANGE IN RETROREFLECTANCE DUE TO A PROXIMAL MIRROR SURFACE
ALSO REFERRED AS LIQUID LEVEL SENSORS
APPLICATIONS
MILITARY AND LAW ENFORCEMENT
NIGHT VISION CAMERA (contd.)
COMPRISES OF :
AMPLIFIED CCD SENSOR
ANTI BLOOMING TECHNOLOGY
CRYSTAL POLYMER SHUTTER
ADVANTAGES :
EXCEPTIONAL DAY LIGHT RESOLN.
IMMUNE TO OVER EXPOSURE
VERY HIGH CONTARAST LEVELS
NO HALOING OR SCINTILLATIONS
BIOMETRICS
YOUR FACE, FINGERS AND EYES IN A WHOLE NEW LIGHT
PARTIAL DISCHARGE DETECTION USES OPTICAL FIBER SENSORS
LETS TAKE A LOOK AT THE CHRONOLOGY OF OPTICAL SENSORS
PUBLICATION AND PATENT TRENDS
GEOGRAPHICAL ORIGIN OF PUBLICATIONS
GEOGRAPHICAL ORIGIN OF OPTICAL SENSOR PATENTS
CONCLUSIONS
LOOKING AT THE INDUSTRY TRENDS IN THE PAST 2 DECADES AND THE EXPONENTIAL CURVE IT SEEMS TO ME THAT THERE IS GOING TO BE A LOT OF RESEARCH AND IMPROVEMENTS TO THE EXISTING SENSORS
OPTICAL SENSORS ARE HERE TO STAY !!!!