Prepared by: Anthony Thomas Dept. of Electrical and Computer Engineering Utah State University

1. ECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Topic: Pressure Sensors Prepared by: Anthony Thomas Dept. of Electrical and Computer Engineering Utah State University E: anthony.thomas@aggiemail.usu.edu; T: (435)787-8723; 3/7/2010

2. Outline • Reference list • To probe further • Major applications • Basic working principle illustrated • A typical sample configuration in application (application notes) • Major specifications • Limitations • And many more relevant issues in applications (such as, how to choose, cost information, where to buy etc.) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

3. Reference list • Digikey (Datasheets) • http://www.digikey.com/ • Omega Engineering, Inc. • http://www.omega.com/ • GE • http://www.gesensing.com/products/npc_100_series.htm?bc=bc_indust+bc_med_fluid • Wikipedia ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

4. Reference list cont. • Maxim • http://www.maxim-ic.com/app-notes/index.mvp/id/871 • Honeywell • http://www51.honeywell.com/honeywell/ ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

5. To explore further (survival pointers of web references etc) • IEEExplore has some good references/papers • Manufacturer websites • Omega.com • They have many types of sensors ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

6. Major applications • Automation & Controls • Hydraulic systems • Automotive • Tire pressure sensors • http://www.marubeni-sys.com/mems/coventor/Pressure_Sensors_Applications.pdf • Aerospace industry • Altitude sensing ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

7. Major applications cont. • Medical • Medical instrumentation • Blood pressure measurement • Infusion pumps • Kidney Dialysis machines ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

8. Basic Working Principles • Many different types of pressure sensors exist • Piezoresistive • Pressure changes shape of sensor, causing a change in resistance • Capacitive • Uses a spring in a push-pull symmetry • Capacitance of one side increases and the other decreases with unbalanced pressures • Electromagnetic ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

9. Basic Working Principles cont. • Potetiometric • Uses a wiper/resistor • Resonant • Uses changes in resonant frequencies to determine pressure changes • Thermal • Uses thermal conductivity of a gas • Pirani gage • Ionization • Measures current from ion flow ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

10. Sample Configuration • Sensor used in industrial control of fluid • Image from Futek ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

11. Sample Configuration cont. • Control system • Image from TI.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

12. Sample Configuration cont. • Measure liquid level ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

13. Major Specifications • Pressure Type • Absolute, Differential, Gauge, switch, vacuum, WC • Operating Pressure • Max/Min values of operation • Port size • Defines physical connection to fluid ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

14. Major Specifications cont. • Output • Analog (Range of values) • Digital (# of bits) • Accuracy • Usually 2% or less • Supply voltage • Voltage needed for sensor ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

15. Major Specifications Cont. • Termination style • Electrical connections such as PCB through hole • Operating temperature • Some go between -50°C and 130°C • Packaging • DIP, SIP, etc. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

16. Limitations • Damage occurs with too much pressure • Flow of fluid affects reading • Sometimes flow is what is desired to sense ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

17. How to choose • Pressure range necessary • Smaller range is usually cheaper • Smaller range is often more accurate • Temperature constraints • Sensor can be damaged at certain temperatures • Power supply requirements • When in mobile applications this can be important ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

18. How to choose cont. • Physical characteristic requirements • Size • Connections • Cost • Quality vs. cost ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

19. Cost • Can be as cheap as $6 or so • Digi-Key Part Number MPXM2102AST1CT-ND • A good variaty around $40 - $100 • Get more expensive • $200 for some good ones on Digikey • Omega has some great ones for around $800 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

20. Where to buy • Digikey (Datasheets) • http://www.digikey.com/ • Omega Engineering, Inc. • http://www.omega.com/ • Futek • http://www.futek.com/apps_pressure.aspx ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators