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Xenics Presentation A 25 minute crash course in Thermography How to improve accuracy / repeatability on non-contact temperature measurement by selecting the right IR spectrum
Copyright 2015 | Guido DEUTZ
Outline Xenics Company Introdcution ~ 3 min Which IR Basics should you be aware of? ~ 6 min
- Atmospheric Windows - Infrared Reflected Light vs. Thermal Imaging vs. Thermography
Where does Thermography reliably works?~ 12 min - Spectral Intensity of ideal IR radiator - Material categories and relevant object criteria
Conclusions ~ 3 min - Benefits of non-contact temperature measurement - What you should have learned ! - Infrared & Thermal IR @ Xenics / Stemmer Imaging
Question & Anwers ~ 1 min 2
Xenics Company Introduction
Xenics Introduction & History
Independent, European supplier of IR cameras & detectors Leading supplier of line-scan and 2D InGaAs SWIR detectors Founded October 16th, 2000 as Spin-off of IMEC
(institute for nanoelectronics of University of Leuven) Profitable since 2004
4
HQ in Leuven (East of Brussels)
Core Competences
5
Detector technology
ROIC design
Electronics
Mechanics
Embedded software
User software
Radiometry
Image enhancement
Mission Statement
6
Our mission is to be a worldwide leading provider of infrared / thermal cameras and SWIR detectors.
Which IR Basics should you be aware of ? Atmospheric Windows Infrared Reflected Light vs. Thermal Imaging vs. Thermography
Atmospheric IR Windows
LWIR: 8 to 14m
SWIR: 0,9 to 1,7 / 2,5 m
MWIR BB: 1 to 5m VisNIR/SWIR: 0,4 to 1,7 m
Overview of atmospheric transmission under typical ambient conditions. Not all radiation can travel free in space. Air transmission distortion results from absorption bands of e.g. water vapor, carbon dioxide etc. Transmission curve depends on air temperature, water vapor (=> e.g. IR use on open sea)
Infrared @ Xenics: Vis = Visible Light VisNIR/SWIR = Visible - SWIR SWIR = Short Wave IR MWIR = Mid Wave IR LWIR = Long Wave (IR) FIR = Far IR
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Im
pac
Infra
red
MWIR: 3 to 5 m
SWIR vs. LWIR Imaging
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X-Ray UV VIS NIR SWIR MWIR LWIR
X-Ray Ultra Violet Visible Near
IR Short Wave Mid Wave
Long Wave
0.01-10 nm
10-400 nm
400750 nm
750-1100 nm
1.1-2.5 um
3.0-5.0 um
7.0-14 um
Dr. Austin Richards Active NIR / SWIR
reflectivity Passive thermal
radiation
Thermal Imaging vs. Thermography Thermal Imaging Thermography
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Non-uniformity correction (NUC) vs. black body (BB) radiators allows: See temperature distribution
on the same surface ! No relative temperature quantification
(= No T on the same surface) No absolute temperature determination
(= No Tabs on surface 1, surface 2, )
NUC + LUT + sensor calibration algorithm on given BB temperature allows: See temperature distribution
on the same surface ! Relative temperature quantification
(= T on the same surface) Absolute temperature determination via
surface emissivity ( ) (Tabs on the same surface) (Tabs on surface 1 vs. Tabs on surface 2, )
Just Imaging Imaging + Temp.Measurement
Colder tire sidewall
Warmer tire shoulder
~ 5 C on tire sidewall
> 30 C on tire shoulder
~ 25C on wheel rim
Hotter wheel rim ?
Where does Thermography reliably works ? Spectral Intensity of ideal IR radiator Material categories and relevant object criteria
Spectral Intensity of ideal IR radiator
Wiens Displacement Law describes that the max. spectral intensity of an emitting black body shifts towards shorter wavelengths as the temperature rises
Copyright 2015 | 12 Thermography introduction
LWIR: 8 to 14m
SWIR: 0,85 to 2,5 m
MWIR: 3 to 5m
NIR: 0,9 to 1,1 m
Plancks Law Radiance over wavelength
Apart of the idealized theory were living in the real world and have to follow real life scenarios
As a matter of fact each material has his individual ability to radiate heat which is called Emissivity and typically used with the letters or e - Remember school physics:
White vs. Black object in the sun. Which object becomes warmer?
Why do we need to speak about Emissivity?
Copyright 2015 | 13 Thermography introduction
Typical Emissivity of Real-Life Objects
Scenario 1: = 0 IR Non-Transparent
100% IR Temp.Signal = Emitted Temp. () + Reflect.Temp () + Transm.Temp. ()
TBackground
TObject
TBehind_Object
Signal
Scenario 2: 0 IR Transparent
100% = + TBackground
TObject
TBehind_Object
Signal
100% = + +
Copyright 2015 | 14 Thermography introduction
Which type of material group exist and what are their typical emissivity's?
So called Non-Metals Typ. Materials:
Plastics Fluids Rubber Painted parts Paper Asphalt Ceramics Wood Textiles Glass Food Coated metals
LWIR: 8 to 14m
NIR/SWIR: 0,85 to 2,5 m
MWIR: 3 to 5m
vs.
Copyright 2015 | 15 Thermography introduction
Which typical material group exist and what are their typical emissivity's?
So called Metals
LWIR: 8 to 14m
NIR/SWIR: 0,85 to 2,5 m
MWIR: 3 to 5m
Typ. Materials: Ferrous Metals
Iron Steel
Non-Ferrous Met. Aluminium Copper Lead Nickel Zinc
vs.
Copyright 2015 | 16 Thermography introduction
Which typical material group exist and what are their typical emissivity's?
IR transparent Materials: Glass (Soda-Lime)
LWIR: 8 to 14m
NIR/SWIR: 0,85 to 2,5 m
MWIR: 3 to 5m
vs.
vs.
Attention: Other sorts of glass (e.g. brown, green, ..) may have a slightly different e-curve!
Copyright 2015 | 17 Thermography introduction
Which typical material group exist and what are their typical emissivity's?
IR transparent Materials: Thin HDPE films (e.g. PE, PP)
Copyright 2015 | 18 Thermography introduction
Attention: Do not measure the background signal by too broad selected IR spectrum
3,43m
Temperature reading errors caused by 10% wrong emissivity settings
Reading error caused by 10% wrong -setting. E.g. TObject = 1.000C TError @ 814m = 80 C TError @ 4,55,5m = 55 C TError @ 2,02,8m = 30 C TError @ 1,41,8m = 20 C TError @ 0,71,1m = 12 C
Recommendation: Select the measurement wavelength
to be as short as possible to increase accuracy and repeatability to
improve reading as good as possible!
Copyright 2015 | 19 Thermography introduction
And in practice?
A practical example for a house man living in Belgium at our booth!
The Xenics 100 C iron OR How to determine emissivity?
Black HighTemp Paint Up to 650C
Silver HighTemp Paint Up to 800C
5mm thick Glass Aluminum Foil
Copyright 2015 | 21 Thermography introduction
Aluminum Foil
A practical example for a house man living in Belgium at our booth!
The Xenics 100 C iron OR How to determine emissivity?
Black HighTemp Paint Up to 650C
Silver HighTemp Paint Up to 800C
5mm thick Glass Aluminum Foil
Copyright 2015 | 22 Thermography introduction
100C e = 100%
50C e = 50%
30C e = 30%
90C E = 90C
Conclusions Benefits of non-contact temperature measurement What you need to be aware of ! Infrared & Thermal IR @ Xenics / Stemmer Imaging
Conclusion: Benefits of non-contact temperature meas.
Thermal IR as non-contact thermometry method allows to: - Measure temperatures on moving objects e.g.
passing car tire and brakes
- Temperature measurement on objects at long distances e.g. rotary kilns in cement industry
- Act w/o reading interference as contact-thermometry e.g. thermocouples on ICs, PCBs,
- Maintenance-friendly sensor as thermocouples will worn-out resp. destroyed in high temperature applications or in aggressive environments
Copyright 2015 | 24 Thermography introduction
Conclusion 1: What you should have learned !
Material categories - IR Non-Transparent
Non-Metals Metals
- IR (Semi-) Transparent Glass Thin plastic foils
Relevant object (material) criteria - Average emissivity at used wavelength
and applicable reading error NIR/SWIR MWIR LWIR
Copyright 2015 | 25 Thermography introduction
Conclusion 2: What you hopefully learned?
What did you hopefully learned today? - Some guys in Belgium have very strange irons - To look at an iron by an infrared device can be a cool thing to do - To handle Emissivity and measure temperatures by IR is easy as
long as I use my brain:
Non-Metals are easy to measure in LWIR due to a good overall emissivity
Metals are okay in NIR/SWIR/MWIR if you take care of background reflections
IR transparent materials e.g. glass or plastics have sometimes weird e-curves. Fist look up for those information before selecting the spectral wavelength. Copyright 2013 | Thermography introduction 26
Infrared & Thermal IR @ Xenics
Xenics offers - Industrial reliable un-cooled & cooled
SWIR / MWIR / LWIR Cameras
- Optional or on-board camera calibration for Xenis Thermography cameras
- Analytic Software End-User Pakages and Windows/Linux SDKs (C# and LabVIEW)
- Dedicated technical support incl. application teams via established sales channel partners
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SWIR Bobcat-Series
LWIR Gobi-Series
MWIR Onca-Series
100% = + +
Xeneth
Reference literature used
Reference and to Infrared-Thermometer Handbook (LTI)
Copyright 2013 | Thermography introduction 28
Full Basics of Physical principles Properties of real
objects Emissivity of
various materials Determining
emissivity of an object
Choosing the spectral response
Thank you for your attention Hope to see you again & Enjoy Thermography !
Xenics PresentationOutlineXenics Company IntroductionXenics Introduction & HistoryCore CompetencesMission StatementWhich IR Basics should you be aware of ?Atmospheric IR WindowsSWIR vs. LWIR ImagingThermal Imaging vs. ThermographyWhere does Thermography reliably works ?Spectral Intensity of ideal IR radiatorWhy do we need to speak about Emissivity?Typical Emissivity of Real-Life ObjectsWhich type of material group exist and what are their typical emissivity's?Which typical material group exist and what are their typical emissivity's?Which typical material group exist and what are their typical emissivity's?Which typical material group exist and what are their typical emissivity's?Temperature reading errors caused by 10% wrong emissivity settingsAnd in practice?A practical example for a house man living in Belgium at our booth!A practical example for a house man living in Belgium at our booth!ConclusionsConclusion:Benefits of non-contact temperature meas.Conclusion 1:What you should have learned !Conclusion 2:What you hopefully learned?Infrared & Thermal IR @ XenicsReference literature usedThank you for your attention
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