ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: Breathalyzers (Breath Alcohol Co

1. ECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Topic: Breathalyzers (Breath Alcohol Content Sensors) Prepared by: Justin Horrell Dept. of Electrical and Computer Engineering Utah State University E: justin.horrell@aggiemail.usu.edu; 3/11/2010

2. Outline • Reference list • Major applications • Basic working principle • Law enforcement application • Major specifications • Electrochemical fuel cell specifications • Limitations • Choosing a breathalyzer • Cost information and variability • Models, cost and where to purchase ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

3. Reference List • http://www.pololu.com • http://www.intox.com/ • http://www.breathalyzer.net • http://www.bactrack.com • http://www.amazon.com • http://www.fuelcell-sensors.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

4. Further Reference • http://www.futurlec.com/Gas_Sensors.shtml • http://www.fctec.com/fctec_basics.asp • http://www.pololu.com/file/download/MQ3.pdf?file_id=0J310 • http://en.wikipedia.org/wiki/Electrochemical_cell • http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/electrochem.html ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

5. Major Applications • Principle technology to measure similar gasses, not just alcohol. Major applications of gas sensors are: • Law enforcement (alcohol) • Mining safety (methane) • CO detection • Air quality control • Hospitals ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

6. Basic Working Principle • Several methods of detecting alcohol gas in breath: • Chemical reaction causing color change • Infrared spectroscopy • Electro-chemical Analysis (using a fuel cell) • Most common application is chemical reaction in a fuel cell, but we will explore all three. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

7. Basic Working Principle • Chemical reaction causing color change • Breath is exhaled by the subject into the device • Alcohol is converted to liquid form by sulfuric acid • Mixture reacts with potassium dichromate to produce a color proportional to the alcohol content • Photocells convert the color difference from reacted mixture to an un-reacted sample to electrical current • Electrical current is converted to a digital display ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

8. Basic Working Principle • Infrared Spectroscopy • Used to identify various compounds within a sample • Molecules are identified based on IR interaction • Breath is exhaled into an laser tube • IR light is sent through the exhaled air • Optical band-pass filter is used to identify ethanol • Electrical current determines alcohol content based on the signal amplitude from the filter ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

9. Basic Working Principle • Electro-chemical Analysis • Breath is exhaled onto a fuel cell • Cell consists of two platinum leads with a porous layer between • Converts alcohol to acid • Creates free electrons • Free electrons are directly proportional to breath alcohol content. http://www.intox.com/images/FC_Schematic.gif ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

10. Law Enforcement Application • Purposes for breathalyzer tests in law enforcement: • Local, state and highway police department road-side DUI determination and arrest • Jails and prisons for testing on inmates • Probation officers to ensure offenders are keeping to the terms of their probation • Work release programs within the prison system ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

11. Law Enforcement Application • Today’s technology relies mostly on Electro-chemical Analysis using fuel cells. • Pros: • Specifically calibrated for human breath • Easy to maintain consistent measurement • Linear response • Low power consumption • Con: • Limited sample amount unable to account for variance ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

12. Major Specifications • We will explore theBACtrack S80 Pro Breathalyzer • Commonly used in Law Enforcement • Quick response time • Accurate with even trace amounts of alcohol • 0.002 – 0.4 % Accuracy range (This is virtually the range from complete sobriety and death) • Accurate with even trace amounts of alcohol • Linear response • Durable and long lasting ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

13. Major Specifications • Specifications of the BACtrack S80 Pro: • Requires Calibration • Runs on two AA batteries. http://lib.store.yahoo.net/lib/breathalyzer-net/bactrack-s80-ownersmanual-5.pdf ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

14. Electrochemical Fuel Cell • BACtrack S80 Pro utilizes electrochemical fuel cell sensor technology as this figure shows http://chemelab.ucsd.edu/fuel04/0b86c2e0.png ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

15. Electrochemical Fuel Cell • The correlation precision of the Peak Output at increasing gas concentrations: http://www.fuelcell-sensors.com/technology.html ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

16. Limitations • Inaccurate readings following eating, drinking or smoking within 20 minutes of using the device • Accurate temperature range is 0-40 C • Requires calibration every 6-12 months • Requires at least 5 seconds of air flow to ensure accuracy ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

17. Choosing a breathalyzer • Determination of which breathalyzer is right for you depends on your application. • Professional such as law enforcement or hospitals should choose a breathalyzer which is • Accurate • Large range of accuracy • Electrochemical fuel cell fits these requirements • Personal use must consider cost, and may choose a less accurate device ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

18. Acquiring a Breathalyzer • We will now go over several different devices which are available for purchase • Consider cost and availability • Determine how much accuracy you need versus cost • Finally we will explore where to purchase a device ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

19. FC20 Portable Breath Alcohol Analyzer • Most accurate fuel cell • Large size • Moderate power • Memory and printing • 0.00-0.60 % BAC • Consumer: $1,380.00 • Call: 1-877-334-6876 to order http://www.breathalyzer.net/fc20kit.html ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

20. BACtrack S80 Pro • Accurate • Small size • Wide range • Low power • 0.00 – 0.40 % BAC • Consumer: $200 • May purchase from the manufacturer: http://www.breathalyzer.net/bactrack-select-s80.html http://lib.store.yahoo.net/lib/breathalyzer-net/S80-box-kit.jpg ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators