February 21, 2003 Team Page 1

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1 Customer: Advanced Thermal Sciences and Sensors Program Mentor: Dr. Edward Hensel Team Members: Jeffrey Gagliardo John Borrelli Fan Ng Derek Schmitt Lisa Wong February 21, 2003 Team Page 1

2 Customer Needs Assess the response of a thermal sensor using a micro sensor array Model dynamic response of a variety of thermal sensors Use experimental data to verify Gurginder Singh s transient finite element model of the sensor response Provide a baseline design to serve as a benchmark for future projects involving high speed, high temperature thermal sensors February 21, 2003 Team Page 2

3 Critical Project Requirements Provide a highly reliable, quantifiable, and verifiable thermal input to the sensor Provide a rapid, near step-change in applied heat flux Acquire data above the Nyquist rate Develop LabVIEW software to acquire data from the thermal sensor array February 21, 2003 Team Page 3

4 Concept Development New Problem, No Process or Product Brainstorming Session Develop system for assessing the dynamic behavior of thermal sensors Generate a variety of concepts limited only by our imaginations Voting Limit list of system concepts Final Concepts Heat Source Sensor / Temperature Distribution Measurement / DAQ February 21, 2003 Team Page 4

5 Concept Development Concept Development Brainstorming Session February 21, 2003 Team Page 5

6 Voting Concept Development 4 votes for heat source options 3 votes for sensor options 3 votes for DAQ options 2 votes for temperature distribution measurement options Final Concepts (Top-Level Designs) Heat Source: Laser, Tube Furnace, Electric Heater, Solar Concentrator Sensor: Thermocouple, PTAT Temperature Distribution Measurement: Thermistor On TC, TC ON TC, TC on PTAT, PTAT on PTAT, PTAT on TC Data Acquisition: MICL Systems and LabVIEW ( February 21, 2003 Team Page 6

7 Feasibility Assessment Concepts for Consideration Energy Source α Solar β Laser δ Electronic Source γ - Tube Furnace Sensor System A- Large Thermocouple with small thermocouples B- Large PTAT with small thermocouples C- Large Thermocouple with small PTATs D- Large PTAT with small PTATs E- Large Thermocouple with small thermistors February 21, 2003 Team Page 7

8 Selection Criteria 1 - Technical Feasibility Group Competence Component Availability 2 - Economic Feasibility Budget Cost / Trial 3 - Schedule Feasibility Delivery Date Relaxation Time 4 - Performance Feasibility Verify Heat Flux Fast Response Severe Environment Modularity February 21, 2003 Team Page 8

9 Scaling Criteria 3 BETTER THAN BASELINE CONCEPT 2 BASELINE CONCEPT 1 WORSE THAN BASELINE CONCEPT 0 FAIL TO MEET BASELINE REQUIREMENT Baseline Concept For: Energy Source α -Solar Sensor System A - Large Thermocouple with small thermocouples February 21, 2003 Team Page 9

10 Summary of Feasibility Assessment Results α. β. δ. γ. P3 P4 Energy Source T1 3 0 T2 E1 P3 P4 Sensor System T1 3 0 T2 E1 A. B. C. D. E. P2 E2 P2 E2 P1 S1 P1 S1 S2 S2 February 21, 2003 Team Page 10

11 Final Concepts Energy Source: Laser Sensor System: Large thermocouple temperature distribution measured with small thermocouples February 21, 2003 Team Page 11

12 Performance Specifications Record data faster than one fourth the time constant of the fastest sensor in the system Provide a known heat flux accurate to +/-5% of the total applied power Time from the end of one experiment to the beginning of the next shall not exceed 20 min. Sensors shall be integrated into the data acquisition systems in the MICL (measurement, instrumentation, and controls lab) February 21, 2003 Team Page 12

13 Performance Specifications (Cont.) Budget shall not exceed $2,000 Components shall be modular, such that, one component may be interchanged with another component of the same type The target fixture shall accommodate most types of temperature sensors The large thermocouple shall have an effective sensing capability between 0ºC and 100ºC February 21, 2003 Team Page 13

14 Performance Specifications (Cont.) Small shielded thermocouples (0.010 or smaller) shall be used on a large thermocouple (0.078 or larger) to sense the response of the large thermocouple The developed LabVIEW software shall be written in such a way that most people with a technical background will be able to operate and configure the software All known safety standards, rules, regulations and laws shall be followed February 21, 2003 Team Page 14

15 System Overview February 21, 2003 Team Page 15

16 Electrical Perspective for Thermocouple Measurements Low-Noise System Amplification Input Filtering Open Thermocouple Detection Cold-Junction Compensation Scanning (Sampling) Differential Measurements Isolation February 21, 2003 Team Page 16

17 Input Filtering: To further reduce noise, a low pass filter should be used. A 1 Hz to 4 Hz filter is useful for removing 50/60 power line noise. For high rate scanning, LPF should be applied to each channel instead of multiplexing them. Linearizing the Data: Use polynomials to approximate the temperature. T = a 0 + a 1 v + a 2 V 2 +a 3 V 3..+a n V n T = a 0 + V(a 1 + V(a 2 + V(a 3 +V ( V(a n -1+Va n ).)))) a 0, a 1, a 2 can be found in Table from NI (National Instruments) Cold-Junction Compensation: V tc (T tc ) = V measured + V tc (T ref ) (After all equation) This technique can further increase accuracy to 0.5 C. February 21, 2003 Team Page 17

18 Mechanical Perspective What if the laser is too powerful and melts the thermocouple? Can the heat flux at a given distance from the laser fiber optic cable be measured accurately? What is the accuracy of the laser lab s heat flux gage? Is there a traceable calibration standard associated with the heat flux gage, and if so, when was the gage last calibrated? What type of material would be best for mounting the sensor? Which setup would give the best results: Sensor mount free to convection Sensor mount embedded in insulation Sensor mount made of a single graphite block February 21, 2003 Team Page 18

19 Heat Flux q = Power/Area For a 15 Watt, 2mm diameter beam q = 4.7 x 10 6 W/m 2 February 21, 2003 Team Page 19

20 Thermocouple Schematic February 21, 2003 Team Page 20

21 Software Block Diagram Device number Array AI sample Channel Conver Temp. to Vol. Linearlization WaveForm Generate Channel Sampling Rate While Loop CJC Senser Cold Juntion Channel AI sample February 21, 2003 Team Page 21

22 Preliminary Design Preliminary Design Sensor/ Power Gage Locator Fixture February 21, 2003 Team Page 22

23 Preliminary Design Sensor Mounting Fixture and Power Gage February 21, 2003 Team Page 23

24 Preliminary Design Pyrolytic Graphite Thermal Conductivity : Parallel to layers: k = K Perpendicular to layers: k = K 300 K : k = 401 W/m-K February 21, 2003 Team Page 24

25 Preliminary Design Laser Fiber Optic Mount February 21, 2003 Team Page 25

26 Preliminary Design Sensor Mount/Power Gage Fixture February 21, 2003 Team Page 26

27 Alignment Preliminary Design February 21, 2003 Team Page 27

28 Cost Projections Quantity Description Unit Price Extended Price 4 Large Diameter Thermocouples Small Diameter Thermocouples Thermocouple Plugs Graphite Target Aluminium Fixture Bucket of liquid plastic Tube of Thermal Epoxy Laser Safety Training Total 1594 February 21, 2003 Team Page 28

29 Gantt Chart For Spring Quarter February 21, 2003 Team Page 29

30 Network Diagram For Spring February 21, 2003 Team Page 30

31 Critical Path For Spring Quarter February 21, 2003 Team Page 31

32 Bibliography 1. American National Standards Institute, American National Standard for the Safe Use of Lasers: ANSI Z (1993), (Laser Institute of America, Orlando, Florida, 1993) 2. Food and Drug Administration: Performance Standard for Laser Products, Center for Devices and Radiological Health, Food and Drug Administration (DHHS), Code of Federal Regulations (CFR), 50, , Tuesday, 20 August Department of Labor: Guidelines for Laser Safety and Hazard Assessment, OSHA Instructional PUB 8-1.7, Directorate of Technical Publications, 19 August R. James Rockwell, Jr. and Jay Parkenson, State and local government laser safety requirements, Journal of Laser Applications, Vol 11, No. 5, pp , (1932). 5. Edmund Industrial Optics, Home page. 14 January 2003 < 6. Kyrotherm, Home page. 14 January JC Whitney Homepage: L=http%3A%2F%2Fwww.jcwhitney.com%2Fproduct.jhtml%3FCATID%3D165345&BQ=j cw2 8. Omega Engineering inc.: 9. Fundamentals of Heat and Mass Transfer. F. Incropera. 5 th Ed. John Wiley & Sons. NY, NY February 21, 2003 Team Page 32

33 February 21, 2003 Team Page 33

34 APPENDIX SLIDES February 21, 2003 Team Page 34

35 Facts When Using Thermocouple Thermocouples generate extremely low voltages, making them susceptible to noise. A thermocouple's temperature sensitivity is small, requiring accurate instrumentation A cold-junction compensation technique is required when using thermocouples. Thermocouples are not as stable as other available temperature sensors. Typical thermocouple accuracy is ~1 C. February 21, 2003 Team Page 35

36 BOM for Candidate Concepts February 21, 2003 Team Page 36

37 V out = V meas V J 2 V J 3 Typical J-type J Thermocouple Layout J3 - Vmeas + J1 IRON J2 CONSTANTAN COPPER Vout=Vmeas-Vj3-Vj2 Vout is the voltage we want February 21, 2003 Team Page 37

38 Cold-Junction Compensation Technique V measured = V J1 (T tc ) + V J3 (T ref )---(1) T TC is the temperature of the thermocouple at J1 T ref is the temperature of the reference junction J2 and J4 are the same temperature The junctions occur in opposite directions, so their total contribution to the measured voltage is zero J3 is the same type as J1 but in the opposite direction - Vmeas + J4 + VJ4 - J3 + VJ3- + VJ2 - J2 + VJ1 - J1 T=Ttc V J3 (T ref )= - V J1 (T ref ) V measured =V tc (T tc ) V tc (T ref )----(2) V measured and T ref is known with the voltage to temperature relationship of the thermocouple, therefore eq. 2 can be solved. Isothermal Region T-Tref IRON CONSTANTAN COPPER February 21, 2003 Team Page 38