ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: Pyroelectric Sensors

1. Prepared by: James Withy Utah State University E: jamesw@cc.usu.edu ECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Topic: Pyroelectric Sensors 3/10/2005

2. Slide-2 Outline • Reference list • To probe further • Major applications • Basic working principle illustrated • A typical sample configuration in application (application notes) • Major specifications • Choosing the right sensor • Cost estimates • Industrial Applications 03/11/05 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

3. Slide-3 Reference list • Electro Optical Components, Inc. • Web Site: • http://www.eoc-inc.com/pyroelectric_detectors.htm • Microsystem Technologies • Web Site: • http://mstmicro.com/sensor/sensor.html • Seattle Robotics Society • Web Site: • http://www.seattlerobotics.org/encoder/200012/pyro.htm 03/11/05 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

4. References (continued) • A, Oden; Processing of Signal of Pyroelectric Sensor in Laser Energy Meter. Measurement Science Review, Vol. 1, Number 1, 2001. • C Harvey, M Veronneau; Pyroelectric Motion Detector,http://www.cem.uvm.edu/~medialab/Spring04/charvey/Senior%20Project/index.htm • Scitec Instruments • Web Site: • http://www.scitec.uk.com/pyroelectric/faq#Q1

5. References (continued) • Acroname • Web site: • http://www.acroname.com/robotics/parts/R1-442-3.html • J L Jones, A M Flynn, B A Seiger, Mobile Robots: Inspiration to Implementation, 2nd Edition, A K Peters, 1999. • Spiricon • Web site: • http://www.spiricon.com/selectionguide/scientific_technology/cameras/pyrocamiii.shtml

6. Slide-6 To explore further (survival pointers of web references etc) • Electro Optical Components, Inc. • Provides extensive selection of sensors and application information. • Web Site: • http://www.eoc-inc.com/pyroelectric_detectors.htm • Measurement Science Review On-line • Provides analytical equations for sensors • Web Site: • http://www.measurement.sk/Papers2/Odon.pdf 03/11/05 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

7. Slide-7 Major applications • Movement detection • Heat Detection • Radiation Detection to tuned wavelenghts (usually in the MIR and FIR range). • Sensors made for Industrial, Commercial, and Millitary applications. 03/11/05 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

8. Basic Working Principle • “The pyroelectric sensor is made of a crystalline material that generates a surface electric charge when exposed to heat in the form of infrared radiation. When the amount of radiation striking the crystal changes, the amount of charge also changes and can then be measured with a sensitive FET device built into the sensor. The sensor elements are sensitive to radiation over a wide range so a filter window is added to limit incoming radiation to the 8 to 14mm range which is most sensitive to human body radiation.”

9. Basic Working Principle (cont'd) • “The sensor has two sensing elements connected in a voltage bucking configuration. This arrangement cancels signals caused by vibration, temperature changes and sunlight. A body passing in front of the sensor will activate first one and then the other element whereas other sources will affect both elements simultaneously and be cancelled. The radiation source must pass across the sensor in a horizontal direction so that the elements are sequentially exposed to the IR source (C Harvey, M Veronneau; Pyroelectric Motion Detector).”

10. (C Harvey, M Veronneau; Pyroelectric Motion Detector)

11. Typical Sample Configuration • At least two crystal media to provide voltage differential and movement direction across field of view • Op-amp amplification stage of initial signal • Thermal compensation circuit • Bandpass filter for specific wavelenghts • Voltage regulator

12. Sample Configuration Circuit

13. Non-Embedded Amplifier Circuit

14. Sample Uses • Robotics for motion detection • Flame/fire detection • Non-Contact temperature detection • Spectrometers • Radiometers • Analytical Instruments • Security/Intrusion detection • Environmental systems • Lighting Controls

15. Field of View Optimization • (taken from Microsystem Technologies Web Site) • Usually fresnel type lenses are coupled with the sensor for different fields of view • Field Ranges • Wide angle (small room) • Extra wide angle (large room) • Narrow angle (hallways, long range)

16. Major Specifications • Number of elements – typically 1, 2, or 4 • Size of elements – varies in 1-2 mm • Voltage or current mode – typically voltage • Amplifier type – typically JFET or OpAmps • Thermal compenstaion – either parallel or serial • Responsivity – 10^2 – 10^5 V/W • Noise Density – 10^-5 – 10^-7 V/Hz ½ • Detectivity – 1-5 8th/cm*Hz^1/2W • Package Type – Canister Packages

17. Example Spec Sheet

18. How to Choose a Sensor • Major factors to consider • Number of sensing elements for application • Voltage swing/temperature range intended for sensor (Responsivity) • Frequency Response (sensor characteristics similar to a low pass filter including a resistor-capacitor network) • Package Type • Impedance matching for preamp circuits (high impedance is usually used in high performance applications)

19. Spiricon Acroname Microsystem Technologies Where to Buy • Companies Include: • InfraTec • Scitec Instruments • Watlow • Mikron Instrument • Detection Systems • Microwatt Applications • Hunter Products • Linear

20. Cost • Typical prices for commercial use range from five dollars for a non-amplified output single sensor unit to about one hundred dollars for an amplified four sensor unit • Arrays for laser calibration in industrial and military applications run in the thousands of dollars

21. Sensor Array • (images from Spiricon web site) • Used in laser beam profiling and calibration

22. Dual Crystal Amplifier • (Electro Optical Components, Inc.)