Understanding Infrared Thermography Reading 3

More documents

Recommendations

Info

■ Thermal Resolution thermal resolution can be measured using a procedure developed for military evaluation of night vision systems. This procedure uses standard resolution targets as illustrated in Figure 4.11 and is described as follows: 1. Set up the test pattern such that ΔT exceeds the manufacturer's specification for minimum resolvable temperature difference. 2. Determine the spatial frequency I t of the target in cycles per milli-radian as follows: a. the number of radians equals the bar width W divided by the distance d to the target (example: 2 mm at 1 m = 2 mRad); and b. the spatial frequency, I t = 1 cycle / (1 bar + 1 space) = 1 / (W + S). (If W = 2 mRad and S = 2 mRad, then I t = 1/(2 + 2) = 0.25 cycles per milli-radian). Charlie Chong/ Fion Zhang
3. Reduce the ΔT until the image is just lost (note ΔT H ) . Raise ΔT until the image is just reacquired (note ΔT C ) then: ΔT = ABS(ΔT H ) + ABS(ΔT C ) 2 4. Then change distances or use different size bar targets to plot minimum resolvable temperature difference for other spatial frequencies. Charlie Chong/ Fion Zhang
Page 1 and 2:
Infrared Thermal Testing Reading II
Page 3 and 4:
Infrared Thermography ~-- ... ... .
Page 5 and 6:
Infrared Thermography Charlie Chong
Page 7 and 8:
See Through & Fun Thermal Camera Ex
Page 9 and 10:
How to see through clothing 2 I'
Page 11 and 12:
Apache IR Thermal Weaponry ■ http
Page 13 and 14:
Charlie Chong/ Fion Zhang
Page 15 and 16:
Greek alphabet Letter Name Sound An
Page 17 and 18:
Greek letter l fl 0 I1 p u w Charli
Page 19 and 20:
SGuide-IRT Content Part 1 of 2 ■
Page 21 and 22:
1.1 Introduction to Principles & Th
Page 23 and 24:
The infrared thermal imaging equipm
Page 25 and 26:
The three modes of heat transfer ar
Page 27 and 28:
The three modes of heat transfer ar
Page 29 and 30:
Temperature and Temperature Scales
Page 31 and 32:
Boston Tea Party - New governances
Page 33 and 34:
The Mighty Fahrenheit & ⅝”, Eng
Page 35 and 36:
Absolute zero is equal to - 273.16
Page 37 and 38:
The Fourier conduction Law expresse
Page 39 and 40:
The Fourier conduction Law ( One di
Page 41 and 42:
Convective Heat Transfer Convective
Page 43 and 44:
Figure 1.2: Convective heat flow T
Page 45 and 46:
Newton's cooling law defines the co
Page 47 and 48:
Radiative Heat Transfer Radiative h
Page 49 and 50:
Figure 1.4: Infrared radiation leav
Page 51 and 52:
Thermal infrared radiation impingin
Page 53 and 54:
Reflections off Specular and Diffus
Page 55 and 56:
Reflections off Specular and Diffus
Page 57 and 58:
Radiant Energy Related to Target Su
Page 59 and 60:
The Stefan-Boltzmann law: W= σƐT
Page 61 and 62:
Figure 1.6: Typical blackbody distr
Page 63 and 64:
1.4 Practical Infrared Measurements
Page 65 and 66:
Characteristics of the Target Surfa
Page 67 and 68:
Referring back to Figure 1.5, the t
Page 69 and 70:
Characteristics of the Transmitting
Page 71 and 72:
Figure 1.10; Transmission of 10m (3
Page 73 and 74:
Figure 1.11: Transmission, absorpti
Page 75 and 76:
Figure 1.12: Transmission curves of
Page 77 and 78:
Chapter 1 Review Questions Q&A 1. b
Page 79 and 80:
Q4. Heat can only flow in the direc
Page 81 and 82:
Q10. The follow ing spectral band i
Page 83 and 84:
Q16. In forced convection, the boun
Page 85 and 86:
Q22. In the 8 to 14 μm spectral re
Page 87 and 88:
2.1 Materials Characteristics A kno
Page 89 and 90:
For an emissivity reference table t
Page 91 and 92:
Errors because of point source refl
Page 93 and 94:
View Angle The angle between the in
Page 95 and 96:
Thermal Conductivity Thermal conduc
Page 97 and 98:
Thermal Diffusivity As in emissivit
Page 99 and 100:
Partial 2.1 Table 2.1: d i'ffusivit
Page 101 and 102:
Partial Table 2.2 Table 2.2: Normal
Page 103 and 104:
Chapter 2 Review Questions Q&A 1. c
Page 105 and 106:
4. When measuring the temperature o
Page 107 and 108:
10. A highly textured surface is sa
Page 109 and 110:
3.1 Thermal Instrumentation Overvie
Page 111 and 112:
Thermopile- Thermoelectric Seebeck
Page 113 and 114:
What is a IR Thermopile? (non-conta
Page 115 and 116:
IR Thermopile Quad Sensor (non-cont
Page 117 and 118:
Thermocouple A thermocouple is a te
Page 119 and 120:
Bourdon Gas Thermometers 5 f\G.3 0
Page 121 and 122:
Liquid Crystal Thermometer A liquid
Page 123 and 124:
Bimetallic Thermometers Dial Spiral
Page 125 and 126:
In RTD devices; Copper, Nickel and
Page 127 and 128:
Platinum Resistance Thermometer Cha
Page 129 and 130:
RTD Materials Different materials u
Page 131 and 132:
Operations of RTD An RTD takes a me
Page 133 and 134:
Benefits of Thin Film RTD There are
Page 135 and 136:
Thermistor +V r===~ Op A p V to A I
Page 137 and 138:
3.2 Contacting Thermal Measuring De
Page 139 and 140:
■ Thermocouple Thermocouples are
Page 141 and 142:
■ Thermistors Thermistors arc als
Page 143 and 144:
3.3 Optical Pyrometers Optical pyro
Page 145 and 146:
Pyrometer A pyrometer is a type of
Page 147 and 148:
Brightness Pyrometers -Wien’s Law
Page 149 and 150:
The processing electronics unit amp
Page 151 and 152:
Infrared Detector An infrared detec
Page 153 and 154:
Figure 3.2: Response Curves of Vari
Page 155 and 156:
The mercury cadmium telluride (HgCd
Page 157 and 158:
Infrared Optics - Lenses, Mirrors a
Page 159 and 160:
Field of View (FOV) A field of view
Page 161 and 162:
What is IFOV? A measure of the spat
Page 163 and 164:
Instantaneous Field of View (IFOV)
Page 165 and 166:
3.5 Scanning and Imaging When probl
Page 167 and 168:
Line Scanning When the measurement
Page 169 and 170:
Two-dimensional Scanning - Thermal
Page 171 and 172:
Figure 3.5: Optomechanlcally scanne
Page 173 and 174:
Pyroelectric Vidicon Thermal Imager
Page 175 and 176:
Figure 3.6: Typical uncooled infrar
Page 177 and 178:
IRFPA Charlie Chong/ Fion Zhang htt
Page 179 and 180:
3.6 Performance Parameters of Infra
Page 181 and 182:
Performance parameters of qualitati
Page 183 and 184:
Temperature Range Temperature range
Page 185 and 186:
Temperature Sensitivity Temperature
Page 187 and 188:
Speed of Response Speed of response
Page 189 and 190:
Figure 3.7: Instrument speed to res
Page 191 and 192:
Figure 3.8: Instrument field-of-vie
Page 193 and 194:
D ≡ αd D = spot size (approximat
Page 195 and 196:
Output Requirements Output requirem
Page 197 and 198:
Spectral Range Spectral range denot
Page 199 and 200:
Spectrall y selective instrumems us
Page 201 and 202:
Figure 3.9: Spectral response of an
Page 203 and 204:
3.7 Performance Characteristics of
Page 205 and 206:
The total field of view for a line
Page 207 and 208:
Instantaneous Field of View IFOV In
Page 209 and 210:
Recalling! Temperature sensitivity
Page 211 and 212:
IFOV - MTF The 0.35 MTF refers to:
Page 213 and 214:
Fig. 2a. Slit Response Function. Ca
Page 215 and 216:
Minimum Resolvable Temperature Diff
Page 217 and 218:
EXAM score! D=σ∙d IFOV ratio = d
Page 219 and 220:
Charlie Chong/ Fion Zhang
Page 221 and 222:
Answer: D= σ•d, IFOV ration= 1/
Page 223 and 224:
Break Time - Kenya Coffee Picker Ch
Page 225 and 226:
Portable Handheld Devices Charlie C
Page 227 and 228:
Temperature sensitivity and readabi
Page 229 and 230:
Hand Held Infrared Module Charlie C
Page 231 and 232:
Note that the laser beam docs not r
Page 233 and 234:
Emissivity set controls, located in
Page 235 and 236:
IR Sensor Module Charlie Chong/ Fio
Page 237 and 238:
IR Sensor Module Charlie Chong/ Fio
Page 239 and 240:
Two-color Pyrometers or Ratio Pyrom
Page 241 and 242:
Page 243 and 244:
Page 245 and 246:
Phenomena which are non-dynamic in
Page 247 and 248:
Some ratio thermometers use more th
Page 249 and 250:
Infrared Radiometric Microscopes Ch
Page 251 and 252:
Line Scanners Line scanners are div
Page 253 and 254:
Special Purpose Devices Special pur
Page 255 and 256:
FLIR- Forward Looking Infrared Char
Page 257 and 258:
Typically, the total field of view
Page 259 and 260:
Pyroelectric devices have no direct
Page 261 and 262:
Figure 3.12: Infrared focal plane a
Page 263 and 264:
Infrared focal plane array imager C
Page 265 and 266:
Infrared focal plane array imager C
Page 267 and 268:
On-board capabilities include isoth
Page 269 and 270:
ccc Electron Microscope Image of mi
Page 271 and 272:
Platinum Silicide IrFPA 19 t«lU 98
Page 273 and 274:
Quantitative IR Image Charlie Chong
Page 275 and 276:
Quantitative Thermal Measurements S
Page 277 and 278:
In addition to the spot measurement
Page 279 and 280:
Stored images can be retrieved, dis
Page 281 and 282:
Calibration Accessories Infrared ra
Page 283 and 284:
Online printers and plotters are re
Page 285 and 286:
Q1. The thermal resolution of an in
Page 287 and 288:
Q7. The 3 to 5 μm spectral region
Page 289 and 290:
Q13. A line scanner can be used to
Page 291 and 292:
Q19. For which of the following app
Page 293 and 294:
Q25. Two-color (ratio) pyrometers m
Page 295 and 296:
Chapter 4 Operating Equipment and U
Page 297 and 298:
■ Emissivity Differences ∆τ Em
Page 299 and 300: Causes of Real Temperature Changes
Page 301 and 302: Mass Transport Differences (Fluid F
Page 303 and 304: Figure 4.1: An indication of water
Page 305 and 306: Thermal Capacitance Differences ∆
Page 307 and 308: ■ Induced Heating Differences (by
Page 309 and 310: Induced Heating Differences Charlie
Page 311 and 312: ■ Energy Conversion Differences E
Page 313 and 314: Figure 4.3: Catalytic reformer vess
Page 315 and 316: Infrared Thermogram Energy Conversi
Page 317 and 318: Infrared Thermogram Energy Conversi
Page 319 and 320: ■ Combination of Heat Transfer Me
Page 321 and 322: Infrared Thermogram of a running mo
Page 323 and 324: ■ Spectral Considerations in Prod
Page 325 and 326: Infrared Thermogram Charlie Chong/
Page 327 and 328: Infrared Thermogram ..... " I Charl
Page 329 and 330: Figure 4.5: Spectral selectivity fo
Page 331 and 332: Figure 4.7: temperature thermogram
Page 333 and 334: Figure 4.8 shows the transmission s
Page 335 and 336: Figure 4.9: Measuring temperature o
Page 337 and 338: IR Filter Charlie Chong/ Fion Zhang
Page 339 and 340: Figure 4.10: Line scanner for conti
Page 341 and 342: Preparation of Equipment for Operat
Page 343 and 344: If the instrument is out of cal ibr
Page 345 and 346: The batteries mentioned on the miss
Page 347 and 348: Comments: ■ ■ ■ Thermal resol
Page 349: Figure 4.11 : Test configuration fo
Page 353 and 354: ■ Imaging Spatial Resolution Imag
Page 355 and 356: A sample setup is illustrated in Fi
Page 357 and 358: 5. If the modulation transfer funct
Page 359 and 360: Figure 4.13: Test configuration for
Page 361 and 362: 4. Open slit until V meas = V max .
Page 363 and 364: ■ Learning the Startup Procedure
Page 365 and 366: ■ Setting the Correct Effective E
Page 367 and 368: Figure 4.14: Test configuration for
Page 369 and 370: ■ Measuring and Reporting Tempera
Page 371 and 372: ■ Recognizing and Avoiding Reflec
Page 373 and 374: ■ Measuring the Appropriate Backg
Page 375 and 376: ■ Temperature Differences Between
Page 377 and 378: ■ Liquid and Compressed Gases Som
Page 379 and 380: Dewar Flask for LN Loosely fitting
Page 381 and 382: ■ Electrical Safety Failure to re
Page 383 and 384: Table 4.1: Electric shock current t
Page 385 and 386: 4.4 Record Keeping Keeping thorough
Page 387 and 388: Easily accessible and easily unders
Page 389 and 390: Q1. Apparent but not real temperatu
Page 391 and 392: Q5. The higher the temperature of a
Page 393 and 394: Q9. Differential thermography can b
Page 395 and 396: 5.1 Overview of Applications Becaus
Page 397 and 398: Electrical Applications Electrical
Page 399 and 400: High electrical resistance is the m
Page 401 and 402:
Excessive heating due to a defectiv
Page 403 and 404:
Inductive currents flowing with in
Page 405 and 406:
Moisture in Airframes The detection
Page 407 and 408:
Process Control and Product Monitor
Page 409 and 410:
The differences produced by this co
Page 411 and 412:
Night Vision, Seareh, Surveillance,
Page 413 and 414:
Thermogram of helicopter taken at n
Page 415 and 416:
Aircraft Under IR Trap Charlie Chon
Page 417 and 418:
Instruments used for these applicat
Page 419 and 420:
8 to 12 μm spectral region over wh
Page 421 and 422:
Animal Studies Body heat allows inf
Page 423 and 424:
Injured equine foreleg (left) appea
Page 425 and 426:
Work energy is expended by friction
Page 427 and 428:
5.4 Fluid Flow Investigations For s
Page 429 and 430:
Figure 1.7: Thermographs of valve (
Page 431 and 432:
■ Building Insulation and Other F
Page 433 and 434:
Figures 5.8 and 5.9 illustrate thes
Page 435 and 436:
Figure 5.9: Example of air exfiltra
Page 437 and 438:
Example of air exfiltration Charlie
Page 439 and 440:
■ Refractory Systems Industrial s
Page 441 and 442:
Refractory Thermogram Charlie Chong
Page 443 and 444:
■ Subsurface Discontinuity Detect
Page 445 and 446:
Figure 5.11: An example of passive
Page 447 and 448:
The equipment necessary to perform
Page 449 and 450:
Figure 5.12: Example of active (hea
Page 451 and 452:
Typical failure modes of the materi
Page 453 and 454:
Figure 5.13: Test of aircraft deici
Page 455 and 456:
DC - 9 Charlie Chong/ Fion Zhang
Page 457 and 458:
Figure 5.14: Conceptual sketch of t
Page 459 and 460:
In this case. however, the heat pul
Page 461 and 462:
Figure 5.15: Erosion/corrosion dama
Page 463 and 464:
737 aircraft Charlie Chong/ Fion Zh
Page 465 and 466:
When there has been adequate solar
Page 467 and 468:
Liquid Level Detection Thermal capa
Page 469 and 470:
Unstimulated and Stimulated Approac
Page 471 and 472:
Subsurface Discontinuity Detection
Page 473 and 474:
1. A major area of infrared nondest
Page 475 and 476:
5. The diagnostics involved in dete
Page 477 and 478:
9. Thermography has been successful
Page 479 and 480:
Appendix A Glossary The following a
Page 481 and 482:
Ambient temperature - Temperature o
Page 483 and 484:
Figure A-1 Apparent ambient tempera
Page 485 and 486:
13.Blackbody, blackbody radiator -
Page 487 and 488:
Alas! Heat Capacity Volumetric = C
Page 489 and 490:
27.Detector, infrared - A transduce
Page 491 and 492:
Thermal Effusivity In Thermodynamic
Page 493 and 494:
Alas! Exitance = Rodiosity for my A
Page 495 and 496:
45.Frame repetition rate - The time
Page 497 and 498:
Thermal Inertia Thermal inertia is
Page 499 and 500:
Instantaneous field of View (lFOV)
Page 501 and 502:
Laser pyrometer - Laser pyrometer -
Page 503 and 504:
Figure 3.2: Response Curves of Vari
Page 505 and 506:
Compare: Minimum resolvable tempera
Page 507 and 508:
86.Radiation rererenee source - A b
Page 509 and 510:
101. Sector - For a line scanner, a
Page 511 and 512:
113. Subtense, angular - The angula
Page 513 and 514:
121. Thermal wave imaging - A term
Page 515 and 516:
125. Thermogram - A thermal map or
Page 517 and 518:
Appendix B Cost Benefit Determinati
Page 519 and 520:
Although the calculations are quite
Page 521 and 522:
96 ASNT Level Ill Study Guide: Infr
Page 523 and 524:
Appendix C, Commonly Used Infrared
Page 525 and 526:
Appendix C, Commonly Used Infrared
Page 527 and 528:
Peach - 我爱桃子 Charlie Cho
Page 529 and 530:
Good Luck Charlie Chong/ Fion Zhang
show all

Understanding Infrared Thermography Reading 3

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?