ULTRASONIC GENERATION AND ITS

APPLICATIONBY AHMED SHAH, M EHSAN AND EHSANULLAH

CONTENTS • INTRODUCTION TO ULTRASONIC • SPECTRUM OF SOUND WAVES• GENERATION OF ULTRASONIC WAVES• PROPERTIES OF ULTRASONIC WAVES• ADVANTAGE AND DISADVANTAGE • APPLICATION AND USES • CONCLUSION

WHAT IS ULTRASONIC WAVES?• ULTRASONICS IS MADE UP OF TWO WORDS “ULTRA” MEANING BEYOND AND

“SONICS” MEANING SOUND.• A SOUND WAVE TRANSMITTED AT A FREQUENCY GREATER THAN 20,000 HZ

PER SECOND, OR BEYOND THE NORMAL HEARING RANGE OF HUMANS. THE SPECIFIC WAVELENGTH IS EQUAL TO THE VELOCITY DIVIDED BY THE FREQUENCY.

ULTRASONIC

SPECTRUM OF SOUND WAVESFREQUENCY DESCRIPTION

EXAMPLE >20 HZ INFRASOUND

EARTHQUAKES

20HZ-20KHZ AUDIBLE SOUND MUSIC

<20 KHZ ULTRASONICS BAT

GENERATION OF ULTRASONIC WAVES• METHODS TO GENERATE ULTRASONIC:• ULTRASONIC ARE GENERATED BY USING OSCILLATORS NAMELY.• 1. PIEZO ELECTRIC OSCILLATOR.• 2. MAGNETO STRICTION OSCILLATOR

PROPERTIES OF ULTRASONIC WAVES• THEY HAVE A LARGE ENERGY CONTENT.• THEY CAN BE TRANSMITTED OVER LONG DISTANCES WITHOUT APPRECIABLE

LOSS OF ENERGY.• VELOCITY OF ULTRASONIC WAVES DEPENDS ON THE TEMPERATURE AND

FREQUENCY OF THE MEDIUM.• JUST LIKE ORDINARY WAVES , ULTRASONIC WAVES GET REFLECTED ,

REFRACTED AND ABSORBED.

ADVANTAGES:-• ADVANTAGES:-• 1.THE DEIGN OF THIS GENERATOR IS VERY SIMPLE & COST IS LAW• 2.AT LOW FREQUENCIES, LARGE O/P IS POSSIBLE WITHOUT THE RISK OF

DAMAGE TO THE OSCILLATORY CIRCUIT.• 3.FREQUENCIES RANGING FROM 100HZ TO 3000KHZ.

DISADVANTAGES:-

• 1.IT CAN’T GENERATE FREQUENCIES OF ULTRASONIC GREATER THAN 3000KHZ• 2.THE FREQUENCY OF OSCILLATION DEPENDS GREATLY ON TEMPERATURE.• 3.THERE WILL BE LOSSES OF ENERGY DUE TO HYSTERESIS AND EDDY

CURRENT.

ONE IMPORTANT APPLICATION HOW TO GENERATE THE ULTRASONIC WAVE ULTRASONIC BASED DISTANCE MEASUREMENT SYSTEM

ULTRASONIC SENSORS (ALSO KNOWN AS TRANSCEIVERS WHEN THEY BOTH SEND AND RECEIVE) SHOWN IN FIGURE WORK ON A PRINCIPLE, WHICH EVALUATE ATTRIBUTES OF A TARGET BY INTERPRETING THE ECHOES FROM RADIO OR SOUND WAVES RESPECTIVELY. ULTRASONIC SENSORS GENERATE HIGH FREQUENCY SOUND WAVES AND EVALUATE THE ECHO WHICH IS RECEIVED BACK BY THE SENSOR

ULTRASONIC SENSOR WAVES

ULTRASONIC SENSOR WAVES

ULTRASONIC SENSOR DISTANCE DETERMINING

• SCIENTISTS HAVE DETERMINED THAT THE SPEED OF SOUND IS APPROXIMATELY 341M/S IN AIR. THE ULTRASONIC SENSOR USES THIS INFORMATION ALONG WITH THE TIME DIFFERENT BETWEEN SENDING AND RECEIVING THE SOUND PULSE TO DETERMINE DISTANCE TO AN OBJECT USING THE FOLLOWING FORMULA

• DISTANCE TO OBJECT =

• T=TIME BETWEEN WHEN AN ULTRASONIC WAVE IS EMITTED AND WHEN IT IS REVISED THAT’S TIME IS CALLED T

HOW IS THE DEPTH OF SEA MEASURED USING ULTRASONIC WAVES?

APPLICATIONS OF ULTRASONIC WAVES•SCIENCE AND ENGINEERING• 1. IT IS USED TO DETECT FLAWS OR CRACKED IN METALS.• 2.IT IS USED TO DETECT SHIPS, SUBMARINES, ICEBERG ETC, IN OCEAN.• 3. IT IS USED FOR SOLDERING ALUMINUM COIL CAPACITORS, ALUMINUM

WIRES AND PLATES WITHOUT USING ANY FLUXES.• 4. IT IS USED TO WELD SOME METALS WHICH CAN’T BE WELDED BY ELECTRIC

OR GAS WELDING• 5. IT IS USED TO CUTTING AND DRILLING HOLES IN METALS.

CONT…….• MEDICINE• 8. IT IS USED TO REMOVE KIDNEY STONES AND

BRAIN TUMORS WITHOUT SHEDDING ANY BLOOD.• 9. IT IS USED TO REMOVE BROKEN TEETH.• 10. IT IS USED FOR STERILIZING MILK AND TO

KILL BACTERIA.• 11. IT IS USED TO STUDY THE BLOOD FLOW

VELOCITIES IN BLOOD VESSELS OF OUR BODY.

CONT….

• ULTRASONIC CAN ALSO SPEED UP CERTAIN CHEMICAL REACTIONS. HENCE, IT HAS GAINED APPLICATION IN AGRICULTURE,

USES OF ULTRASONIC • ULTRASONIC CLEANERS ARE USED AT FREQUENCIES FROM 20 TO 40 KHZ FOR• JEWELRY, • LENSES • OTHER OPTICAL PARTS,• WATCHES, DENTAL INSTRUMENTS• SURGICAL INSTRUMENT • DIVING REGULATORS AND INDUSTRIAL PARTS.

CONCLUSION • ULTRASOUND IS USED IN MANY DIFFERENT FIELDS.

ULTRASONIC DEVICES ARE USED TO DETECT OBJECTS AND MEASURE DISTANCES. ULTRASONIC IMAGING IS USED IN BOTH VETERINARY MEDICINE AND HUMAN MEDICINE. IN THE NONDESTRUCTIVE TESTING OF PRODUCTS AND STRUCTURES, ULTRASOUND IS USED TO DETECT INVISIBLE FLAWS. INDUSTRIALLY, ULTRASOUND IS USED FOR CLEANING AND FOR MIXING, AND TO ACCELERATE CHEMICAL PROCESSES. ANIMALS SUCH AS BATS AND PORPOISES USE ULTRASOUND FOR LOCATING PREY AND OBSTACLES.