Earthquake Detector Using the Michelson Interferometer The Mid-South

Earthquake Detector Using the Michelson Interferometer The Mid-South Annual Engineering and Sciences Conference MAESC 2006 Memphis, Tennessee Haoyan Bill Lan March 31, 2006

Every Day Deep underground

America's most destructive earthquakes since the turn of the 20 th century: Last Decade

People Are at Risk Researches need to be done there are 70, 000 buildings in state of California alone that could sustain major quake damage Experts predict there will be a major earthquake in state of California before year 2024

For those who lives there It would be nice…. If……

Earthquake Detector Prototype Optical Power Meter Analog to Digital Interface and LED Displays Michelson Interferometer UP 3 Board with a Cyclone Microprocessor

Project Concept Michelson Interferometer Light Intensity Measuring Device Analog to digital interface Major part of the project Central processing unit UP 3 board (Quartus II) Alarm System and back up power supply 4 Digits 7 -Segment LED Display

Screen Matrix for Different Needs

3 D View of an Interferometer Sensor of Light Intensity Measuring Device Bright Fringe Mirror#2 Stationary Dark Fringe Beam Splitter He Ne Laser Beam Generator Dispersion Lens Move Mirror#1 to cause the fringe movement

How does it work? Mirror#2 Stationary Mirror#1 Moving

Bright Fringe Dark Fringe

Sensor of Optical Power Meter Dial for Moving Mirror Movement of Mirror#1 generates fringe movement

Need fringes number to calculate the wavelength Fringe movements not be counted using naked eyes The sinusoidal wave has a frequency approx. at 100 Hz

The way to measure the spectral of the light is where d is the distance M 1 has been moved and n is the number of the fringes and Lambda is the wavelength of the laser beam.

How does this work? a single tap on the table will cause rapid movement of the fringes this property can be used to detect a potential earthquake

Sinusoidal wave from the optical power meter Offset Voltage Output wave form goes into the UP 3 board

Design of an Analog to Digital Interface Adjustable offset voltage TTL output

Project Concept Michelson Interferometer Light Intensity Measuring Device Analog to digital interface Major part of the project Central processing unit UP 3 board (Quartus II) Alarm System and back up power supply 4 Digits 7 -Segment LED Display

Altera UP 3 board is setup in the lab Microprocessor is Programmed via a PC Input from Analog to Digital Interface Output to 4 -digits Displays

Circuit Design using Quartus Output of the Unit Digit Input from Analog to Digital Interface Output of the Hundredth Digit Output of the Tenth Digit Output of the Thousandth Digit

Decade Counter Decoder Input A 74143 chip

LED Digit Displays 7 -Seg LED Display

Prototype Testing Simulate an earthquake Tester tap table with his/her finger

Since Lambda for a He-Ne laser beam is 632 nm For each fringes (n=1), we are moving Theoretically we are detecting vibration on 1/3 um scale

Put 1/3 um into a prospective scale Human hair avg. 65 um in Diameter Vibration of 1/3 of this Scale

Prototype Estimated Cost Interferometer $700 Light intensity detector $150 Quartus II and software $300 Other parts and hardware $50 Total cost $1200

Estimated Production Cost Interferometer $100 Light intensity detector $50 Burn-in Chips $10 Other parts and hardware $50 Total cost ~$210 Instead of the $300 UP 3 Board

References http: //www. 3 dimagery. com/3 dmichelson. ht ml http: //www. latimes. com/business/la-mequake 8 sep 08, 0, 3035306. story http: //www. altera. com/education/univ/stud ents/unv-students. html http: //www. space. com/scienceastronomy/a stronomy/interferometry_101. html

Questions And Comments?

Prototype Testing Continues Simulation of a fire disaster has been conducted as well A pressure changing device has been used