1. May 30 , 2013Presenter: Gary Malhoit, P.E.1 2. Agenda Why Infrared? Infrared Basics Power Quality, Heat & Reliability Questions & Comments: All2 3. Heraclitus (535-475 BC)3No man ever steps in the same river twice." 4. National Fire ProtectionAssociation The National Fire Protection Association (NFPA) wasestablished in 1896 by concerned losses due to fires. A primary cause of industrial fires and losses, as wellpersonal injury accidents, over the last five decades isrelated to electricity. NFPA recommends that routine infrared inspectionsof energized electrical systems should be performedannually.4 5. Case for Using Infrared Generally Non-Invasive Process (Safety) Improve Power Quality by Identifying Poor ElectricalConnections (Voltage Drop Issues) Improve Power Quality by Identifying High NeutralCurrents Reduced Risk of Unplanned Outages (Reliability) Reduced Risk of Fire (Insurance Discounts)5 6. Prioritize Infrared Work6 7. Alpha and Beta Risks7 8. Poor Connections & Heat8Non-ConductingHot Conducting Cross-Section (A)Conductor Cross-SectionsHotterHot Conducting Cross-Section (A)Non-Conducting 9. Heat & Diminishing Reliability9FailureRateTimeInfantMortalityNormal Life Wear OutHeatBathtub curve derived from threeWeibull Distributions 10. Some Types of Connections10Bolted ConnectionsClip ConnectionsCrimp & Bolted Connections 11. Fuse Clamps11 12. Heat Transfer Conduction ConvectionRadiation12Source: Earthforce.com 13. Electromagnetic Spectrum Light comprises only a small portion of the entireelectromagnetic spectrum. Most of the electromagnetic spectrum is invisible tothe human eye.13 14. Hot Steel Glowing IncludesEmitted Energy Hot steel emitting light or energy in at least the visibleportion of the electromagnetic spectrum. Not all hotmetals glow visually like steel, for example aluminum.Emitted Energy= K T414 15. Herschels Experiment (1800)15Blue: 80 degreesYellow: 83 degreesInfrared: 86 degreesSource: FLIR Course Manual 16. Opaque and Transparent Transmitted light is limited to transparent objects. The frequency of the electromagnetic energy sourcecan determine if an object is opaque or transparent.Opaque TransparentAbsorbedAbsorbedReflected ReflectedTransmitted=0Transmitted=016Germanium GlassVisible Light Visible Light 17. 17Opaque TransparentOpaque and Transparent(cont.)Source: FLIR Course Manual 18. Commonly Used InfraredWavelength (Microns)18Near IRLong IRMid IR NotUsedNotUsed(Used for Thermography)Source: FLIR Course Manual 19. Above Absolute Zero All objects emit infrared above absolute zero The warmer the object, the greater the intensity ofemitted infrared radiation.19Source: FLIR Course Manual 20. What is a Blackbody? A blackbody is a perfect or ideal absorber or emitterof radiation at a temperature above absolute zero. In reality, a black body does not exist.20If dBlackbody RadiationReflection & DiffractionOpening (diameter=d) 21. Emissivity () Emissivity is the ability of an object to emit radiationand is the ratio of emission from an object ascompared to a black body. Emissivity of a Blackbody is 1.Emissivity = =Actual Emission from Object at temperature TEmission from Blackbody at temperature T21 22. Emissivity of CommonMaterials at 300Kelvin Aluminum Foil .04 Masonry Plastered 0.93 Nickel 0.03 Paint 0.96 Glass 0.93 Tile 0.97 Copper 0.03 Granite 0.45Note: Metals have a low emissivity!!22 23. Emitted, Apparent & ReflectedApparent Temperatures23Emitted TemperatureApparent TemperatureReflected ApparentTemperature (RAT)(1-)TargetCameraAttempt to match the emissivity setting of the camera to theemissivity of target.Reflectivity 24. Plancks Law (1900) Classical theory called for infinite energy at the higherfrequencies and is referred to as the Ultravioletcatastrophe Max Planck determined electromagnetic energy isemitted in discrete packets of energy proportional tofrequency24Source: WikipediaDepicted curvespresume blackbodies 25. Camera Schematic25ProcessorTarget Filter SensorInfraredVisible, RATTApparentTe 26. IR Detector DevicesIR detectors consists of generally two types of devices: Un-cooled Most common and functions at roomtemperature and is generally made using compoundsemiconductors (e.g., Lead Selenide & IndiumAntimonide). Cryogenically cooled - More expensive and moreaccurate though more susceptible to damage andrequires cryogenically cooling.26 27. Transparent Windows27 28. Grayscale PaletteWatertown, MAApril 19, 201328 29. Ironbow Palette29 30. Rainbow Palette30 31. Electrical Tape on Three MetalCans Electrical Tape (.95) has much higher emissivity thanmetal (.2) of can.Visual InfraredHotCanCan atRoomTemp.ColdCanHotCanCan atRoomTemp.ColdCan31 32. Priority Rating Table32= 96 F 33. Loaded Circuit33 34. Viewing through Camera34 35. Poor Fuse Connection35 36. Third Harmonics36 37. Harmonics & Heat(Skin Effect)37DC: No Skin Effect 60 Hz: Skin Effect 1 KHz: Substantial Skin EffectRegion of most current flow=Skin Depth 38. Third Harmonics (cont.)38Could be unbalanced Situation? 39. Loose Neutral39 40. Heat Pattern Dissipates fromLose Connection40 41. Inductive Heating: Iso-PhaseBus41 42. 42Strap Between Section of ISOPhase Bus 43. Infrared Applications43Source: Wall Street Journal 44. Future of Infrared44 45. Comments & Questions?45