fluke thermal imaging seminar utility

7/27/2019 Fluke Thermal Imaging Seminar Utility

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Fluke Thermal Imaging Company Confidential 1

Thermography- Understanding our thermal world


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Agenda

Thermography What, Why and Where

Applications

How a Thermal Imager works How Does an Imager Measure Temperature

Thermography Physics and Heat Transfer

Resolving detail and capturing a good image

Additional training & support

Imager hands-on

Questions?


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What is Thermography?

It is the science of seeingtemperatures by measuringthe radiation emitted from agiven surface and convertingthis data to a corresponding

digital, or visual image Infrared radiation is emitted by

all objects based on theirtemperature

The amount of radiationincreases with temperature

We are only measuring thesurface temperature


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Why use Thermal Imaging?

Hot or cold areas, or thermal anomalies, oftenare a strong indicator of equipment health.

Allows maintenance personnel to become moreproactive and less reactive.

Thermal Imaging works well to inspect: Electrical Equipment

Mechanical Equipment

Heating/Cooling Equipment

Building Envelope

Electronic circuits and boards Medical/Health screening

Other!


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Temperature Measurements

Fast, safe and accurate non-contactmeasurements can be obtainedfrom objects even if the are:

moving or very hot

difficult to reach

expensive to shut-down

dangerous to contact

contaminated or altered if contacted


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Downtime is expensive

Industry Sector Revenue/Hour

Chemicals $704,101

Construction and Engineering $389,601

Electronics $477,366 Energy $2,817,846

Food/beverage processing $804,192

Manufacturing $1,610,654

Metals/natural resources $580,588

Pharmaceuticals $1,082,252

Utilities $643,250

Source: Jacksonville Power Authority


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Power Transmission & Distributionapplications


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Substation transformers

Notetemperaturedifference


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Substation transformers

9


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Some cooling

tubes appear tobe plugged

Transformer Cooling


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Pad-mount transformers

Look for consistenttemperaturesacross all elbows


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Transformers elbows

Look for problems in both internal and external

connections


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Hot bushing


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Pole transformer


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Transformer

problem easilyidentified from adistance

Pole transformer connection


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Utility Connection


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Utility connection


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Electrical panels and circuits

Overloaded systems orexcessive current

Loose or corrodedconnections

Component failures Wiring mistakes Under-specified components Power quality problems like

phase unbalance, overload

or harmonic distortion Insulation failuresImage shown here is Picture-In-

Picture (PIP) mode where center of image is IR surrounded by visible


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Thermography helped distinguish between

loose connection and overloaded circuit

Overloadedcircuit fuse

hot on bothends

Looseconnection,fuse hot onone end only

Courtesy of Snell Infrared


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IR inspection windows

IR windows provide faster, safer equipmentinspections

High-voltage Switchgear

Medium-voltage Switchgear

Dry-Type Transformers

Motor Control Centers

Other areas where Arc Flash Hazard exists


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Breaker Panel

Two lighting breakers are 35F above ambient


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In the beginning

In 1800, Sir William Herscheldiscovered that by passing sunlightthrough a glass prism andmeasuring the temperature of thecolors, the temperature increasedfrom the violet to the red part of thespectrum.

He decided to measure the areasjust beyond the red portion and thiswas the highest temperature of all!

He found these calorific rays,

which existed beyond visible light,were reflected, refracted, absorbedand transmitted just like visible light

These rays were re-named infraredradiation prefix means below
http://images.google.com/imgres?imgurl=http://www.physics.ohio-state.edu/~gilmore/images/collection/misc/prism.gif&imgrefurl=http://www.weblo.com/domain/available/alexisdziena.com/&h=341&w=576&sz=5&hl=en&start=2&tbnid=agyJykIFia8pbM:&tbnh=79&tbnw=134&prev=/images%3Fq%3Dprism%26gbv%3D2%26hl%3Den


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Infrared Radiation

Infrared radiation is electromagnetic radiation withwavelengths longer than visible light but shorterthan microwaves

Infrared radiation is radiated heat that cannot beseen by our eyes but can be sensed by our skin

All objects, whatever their temperature, emit infraredradiation

The intensity of infrared radiation depends on thetemperature and a surface property termedemissivity

When an object reaches approximately644C(1200F) visible light is emitted


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Infrared spectrum

IR atmospheric transmission bands

Long-wave 8-14Mid-wave 2-6

Infrared wave RadioUltra-violet

X-raysGamma-rays

Visible light


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jumping forward

Honeywell was a major supplier of militaryinfrared systems in the 80s but the detectorsrequired cooling to -340F

Received $12 million of top-secret contracts to developed a

long-wave infrared detector array technology that required nocooling

First to develop the microbolometer

Sold large infrared products division in 1989

Military declassified the use of microbolometer technology in1992

Licensed microbolometer technology to other manufacturers


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Fluke Thermal Imaging Company Confidential 28XXX Elements

XXXElements

Each of the thousands of elements, or pixels, contain anaccurate temperature value. The Imager, through the use of acomplex set of algorithms, assign specific colors thatcorrespond exactly with the temperature value found at thespecific X Y coordinate.

How do we get a picture?

Some cameras save a simplepicture which does not actuallycontain any measurements.

Fully radiometric cameras storethe actual temperaturemeasurements which can bebrought into a PC later foranalysis.


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How does it work?

19,200 detectors or more arefabricated into a two-dimensional array called aFocal Plane Array (FPA)

Each individual detectormeasures the incomingradiation and converts thisdata to a thermogram, orvisual image, which we usefor detailed temperatureanalysis and documentation.

Its likehaving

Thousandsofinfraredthermometers inone instrument


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Distance to Spot Ratio D:S

1 ft.

30 feet

Distance to Spot Ratio is distance from instrument to the objectcompared to the size of the the spot being measured

30:1


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Reflection, Absorption and Transmission

What happens when IR radiation strikes a surface?


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Radiometric measurementsRadiosity

Radiation can be transmitted through asurface

Our IR camera lens, for example

Does not change the temperature of the surface!

Radiation can be reflected off a surface

Remember our glass window example? Does not change the temperature of the surface!

Radiation can be absorbed and re-emitted Amount of energy absorbed = re-emitted

This is what we measure with our IR camera!

Reflected+ Absorbed+ Transmitted = 1

Known as the RAT law Can also say R+E+T=1 Reflected

Transmitted

Absorbed

Re-emitted


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Radiometric measurements

0.03 Reflected

0.97 Re-Emitted

T=0

0.60 Reflected

0.40 Re-Emitted

T=0

The camera sensor detectsinfrared radiation

Only the emitted radiationtells us about surface

temperature. Different surfaces absorband emit radiation differentlythis is called emissivity

Adjusting emissivity valueand background tempimproves accuracy.


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Emissivity ( )

Pronunciation: "Em`is*siv"i*ty Definition: scientific measurement of the abilityfor absorbed heat energy to radiate (leave) anobject as compared to a black body at the

same temperature a true black body radiates 100% of its absorbed energy

(nothing is reflected or transmitted) so the = 1

A perfect reflector would have an = 0

Materials that are not black bodies only radiatea fraction of the radiation as a black body atthe same temperature and wave length so the is


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Selecting the Correct Emissivity Value

Rules of thumb Use 0.95 for all painted target surface independent of color If unpainted or un-corroded metal use 0.2 or lower Reliable measurements when emissivity is > 0.6 Known or controlled background temperature

Apply tape or paint to increase emissivity

Values for common materials are found in the imagerowners manual, in the PC software, internet sources andon some Imagers

If the target emissivity is unknown use the Imager tomeasure it

Use the tape method


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Emissivity of Target Surfaces

Emissivity Values (samples)

Aluminum, polished 0.05 Platinum 0.08

Brick 0.85 Rubber 0.95

Bronze, polished 0.10 Snow 0.80

Bronze, porous 0.55 Steel, galvanized 0.28

Copper, oxidized 0.65 Steel, rolled 0.24

Copper, oxidized to black 0.88 Steel, rough 0.96

Skin 0.98 Tin 0.05

Nickel 0.05 Tungsten 0.05Paint 0.94 Water 0.98

Paint, silver finish 0.31 Zinc, sheet 0.20


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Be aware: wind can effecttemperature

85F 76F 72F

15 mph windT = 13F

117F 95F 81F

No windT = 36F


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Wind Effects

Wind can significantly reduce temperature of hot spot Rule of thumb

10mph can reduce T by up to 1/2 15mph can reduce T by up to 2/3

Roof moisture inspection is very difficult in wind 03 Little or no drifting of smoke 47 Wind felt on face, leaves rustle, weather vane moves 812 Leaves in constant motion, small flags are extended 1318 Wind raises dust and paper, small branches move 18 + Thermally - go home!

Beaufort wind scale gives more detail on estimatingwind speed


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Parameters for a Good Image

Composition Focus Level and Span

Palette Distance

IFOV/IFOVmeas

System load Camera settings

Calibration


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Focus is CRITICAL

IR imager focus is less sharp than a visible camera far more elements in a visible detector array

Infrared images are naturally less sharp

* IR wave lengths are more than an order of magnitude longer

* visible light cameras generally measure reflected radiation notemitted; IR imagers must measure emitted radiation to determinetemperature

* sharp edges can exist between a black line and a white line butsharp edges can not exist between a hot line and a cold line

Best focus is critical for accurate temperaturemeasurements

Anything but focus can be modified/optimized later withPC software


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FOV, IFOV, IFOVmeas

Fluke


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Measurement Accuracy

Field of View (FOV) is totaltarget area seen by imager

Instantaneous Field of View(IFOV) is the smallest areawhich can be seen by the

imager (Spatial Resolution orspot size)

Measurement InstantaneousField of View (IFOVmeas) isthe smallest area an imagercan measure and is usually 2-3 times smaller than IFOV

Determined by number ofsystem properties, not just thepixel resolution

115.9

120.2


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Checking calibration

Routinely check basiccalibration before eachscan.

Here are a few simple testyou can perform

Check the tear duct of a workpartner (recommend the sameperson)

Check an ice bath to verifycamera performance at 0 C

Check boiling water to verify

camera performance at 100 C Acquire a blackbody reference

in one of your common tempranges


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80s vintage portablethermal imager

Display

Detector

Cooling gas

Early thermal imager


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Selecting an IR Camera

What is the application?How will it be used?

Considerations: Thermal Sensitivity

Detector Size

Ease of Use

IR Fusion Technology

Ruggedness & reliability

Screen Size Software

Total Cost of Ownership


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What is IR-Fusion ?

IR-Fusion links the Thermal Image withthe Visual Image

Easier to understand what you are looking at

* See the context

* Read any markers/labels/text

* No laser pointer needed Easier to report findings to others

* No need to also take a picture with a normalcamera

Helps you focus the Thermal Imager better

* The Thermal Imager is focused correctlywhen the Thermal and Visual images arecompletely aligned


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PC Software

Software provides image:

archiving

enhancement

analysis

annotation

report generation


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Additional training and information

Fluke Thermal Imaging Training Center www.fluke.com/titraining

Hands-On Seminars

The Snell Group: Online Training

* Pre-Recorded Webinars from $39 to $79

Level 1, 2 & 3 Thermography Training

Application Specific Training

www.snellgroup.com
http://www.fluke.com/titraininghttp://www.snellgroup.com/http://www.snellgroup.com/http://www.fluke.com/titraining


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Thanks for attending!

Questions?

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