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 02020 Page 1
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 02020 Page 2
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 02020 Page 3
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 02020 Page 4
Concept Development Concept Development Brainstorming Session February 21, 2003 Team 02020 Page 5
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 (http://www.rit.edu/~micl/) February 21, 2003 Team 02020 Page 6
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 02020 Page 7
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 02020 Page 8
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 02020 Page 9
Summary of Feasibility Assessment Results α. β. δ. γ. P3 P4 Energy Source 2.5 2 1.5 1 0.5 T1 3 0 T2 E1 P3 P4 Sensor System 2.5 2 1.5 1 0.5 T1 3 0 T2 E1 A. B. C. D. E. P2 E2 P2 E2 P1 S1 P1 S1 S2 S2 February 21, 2003 Team 02020 Page 10
Final Concepts Energy Source: Laser Sensor System: Large thermocouple temperature distribution measured with small thermocouples February 21, 2003 Team 02020 Page 11
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 02020 Page 12
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 02020 Page 13
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 02020 Page 14
System Overview February 21, 2003 Team 02020 Page 15
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 02020 Page 16
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 02020 Page 17
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 02020 Page 18
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 02020 Page 19
Thermocouple Schematic February 21, 2003 Team 02020 Page 20
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 02020 Page 21
Preliminary Design Preliminary Design Sensor/ Power Gage Locator Fixture February 21, 2003 Team 02020 Page 22
Preliminary Design Sensor Mounting Fixture and Power Gage February 21, 2003 Team 02020 Page 23
Preliminary Design Pyrolytic Graphite Thermal Conductivity : Parallel to layers: k = 1950 W/m-K @ 300 K Perpendicular to layers: k = 5.70 W/m-K @ 300 K Copper @ 300 K : k = 401 W/m-K February 21, 2003 Team 02020 Page 24
Preliminary Design Laser Fiber Optic Mount February 21, 2003 Team 02020 Page 25
Preliminary Design Sensor Mount/Power Gage Fixture February 21, 2003 Team 02020 Page 26
Alignment Preliminary Design February 21, 2003 Team 02020 Page 27
Cost Projections Quantity Description Unit Price Extended Price 4 Large Diameter Thermocouples 16 64 30 Small Diameter Thermocouples 7 210 40 Thermocouple Plugs 2.50 100 1 Graphite Target 50 50 1 Aluminium Fixture 100 100 1 Bucket of liquid plastic 40 40 1 Tube of Thermal Epoxy 30 30 1 Laser Safety Training 1000 1000 Total 1594 February 21, 2003 Team 02020 Page 28
Gantt Chart For Spring Quarter February 21, 2003 Team 02020 Page 29
Network Diagram For Spring February 21, 2003 Team 02020 Page 30
Critical Path For Spring Quarter February 21, 2003 Team 02020 Page 31
Bibliography 1. American National Standards Institute, American National Standard for the Safe Use of Lasers: ANSI Z-136.1 (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, 33682-33702, Tuesday, 20 August 1985 3. Department of Labor: Guidelines for Laser Safety and Hazard Assessment, OSHA Instructional PUB 8-1.7, Directorate of Technical Publications, 19 August 1991. 4. R. James Rockwell, Jr. and Jay Parkenson, State and local government laser safety requirements, Journal of Laser Applications, Vol 11, No. 5, pp. 225-231, (1932). 5. Edmund Industrial Optics, Home page. 14 January 2003 <http://www.edmundoptics.com/iod/displayproduct.cfm?productid=2040>. 6. Kyrotherm, Home page. 14 January 2003 7. JC Whitney Homepage: http://www.jcwhitney.com/product.jhtml?catid=165345&aid=8808847&pid=523995&ur L=http%3A%2F%2Fwww.jcwhitney.com%2Fproduct.jhtml%3FCATID%3D165345&BQ=j cw2 8. Omega Engineering inc.: http://www.omega.com/temperature/ 9. Fundamentals of Heat and Mass Transfer. F. Incropera. 5 th Ed. John Wiley & Sons. NY, NY. 2002 February 21, 2003 Team 02020 Page 32
February 21, 2003 Team 02020 Page 33
APPENDIX SLIDES February 21, 2003 Team 02020 Page 34
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 02020 Page 35
BOM for Candidate Concepts February 21, 2003 Team 02020 Page 36
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 02020 Page 37
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 02020 Page 38