ITC InfraMation - = December 2003

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December=20 2003

Volume 4, Issue=20 12

In This=20 Issue:=20

Welcome

IR in the News

ITC Website Message Board Posts

How=20 The Eyes (and IR camera) Can Be Misled

Brainteaser of the Month

Last Month's Brainteaser

Past Issues

Upcoming Classes

About the ITC

Season's=20 Greetings {{user("firstname")}},

It's that time of = the year again,=20 the air has a chill and we are all busy getting ready for the = holidays;=20 and we have another great issue for you this month.

Thanks to all=20 of the InfraMation delegates who completed our survey. We got = great=20 feedback and some ideas for next year.

Our bulletin=20 boards have been busy this last month. Check out the latest posts.

Our=20 application article this month tells how you can sometimes = come to=20 the incorrect conclusion from your thermal image if you don't do a = little=20 more digging. See "How The Eyes (and IR camera) Can Be Misled" by = Joe=20 Gierlach at TEGG Corporation.

And=20 we have another Brainteaser for you at Brainteaser of the Month.

If you want to=20 save this newsletter for viewing off line in your computer, just = go to the=20 web page using=20 your browser and select File....Save As or save this email = page as html in=20 your email software.

Spend some=20 quality time with your loved ones this holiday season. = We'll see you=20 again next year!

Gary=20 Orlove,
Editor and = Publisher

IR in the=20 News [top]

THERMACAM=AE =96 The Alternative to Exhaustive=20 Testing
Process = &=20 Control Today, UK - Nov 26, = 2003
Thermal=20 imaging has increasingly become a key tool at Land Rover = for the=20 early ... Without thermography there would only be = evidence of total failure at the end of ...
The Truth Lies in = Technology
TechNewsWorld - Nov 10,=20 2003
... In Rochester, Minn., in 2001, endocrinologist = James=20 Levine was performing obesity research by using a=20 thermal-imaging camera that observes how much heat = is=20 ...
Important Incan comples discovered = near Machu=20 Picchu
The = Arbiter=20 Online - Nov 10, 2003
... A = re-examination of=20 Bingham=92s expedition notes in the Yale archives, combined with = thermal imaging studies conducted from a = low-flying=20 Cessna, allowed ...
What is RSD?
Times Press, IL - Nov 7,=20 2003
... RSD is diagnosed primarily through = observation of the=20 symptoms. Some physicians use thermography to detect = changes in=20 body temperature that are common in RSD. ...=20

ITC=20 Website Message Board Posts [top]

We recently = overhauled the=20 Infrared Training Center website. We have a = new design,=20 improved user interface, new features, and it runs much faster. = Among the=20 new features are a thermal image gallery and = redesigned=20 message=20 boards.

Below you will=20 find a selection of new topics started by visitors to the message = board=20 last month. Feel free to click the links, see how people have = responded,=20 and post your own response.

Hea= t=20 Detection Underwater
I am trying to determine if the heat = of a=20 human body or of a motor engine located underwater could be = detected or=20 visualized using infrared sensors or cameras, and whether the = sensors or=20 camera can be located several feet away from the heat source, e. = g, 2 to=20 10 feet away. If the answer is yes, do the sensors/camera need = to be=20 underwater too? or airborne detection is also possible? =
EIF= S=20 wall scans
I tried to scan a wall system comprised of a = rigid=20 foam insulation and a synthetic stucco covering. My scans = were=20 inconclusive. Does anyone have specific experience to = share?=20
CAL= IBRATION=20 inquiry for Model: FLIR THERMACAM PM695
What is the = CALIBRATION=20 procedure for Model: FLIR THERMACAM PM695 TYPE: THERMOSCANNER. = Can=20 anyone help us?
Ref= erence=20 temperature, background temperature
The reference = temperature=20 setting in my ThermaCAM PM575 camera can be done manually. I am = not sure=20 what the reference temperature is referencing or if I am = confusing it=20 with background temperature. I am concerned about having = inaccurate=20 measurements.

And of course=20 if YOU have a question or want to start a discussion on a = topic, we=20 would love to hear from you. Just post a new thread on the message = board.

How = The Eyes (and=20 IR camera) Can Be Misled [top]

By Joe Gierlach
Manager - = Technical=20 Training & Support
TEGG Corporation

The = IR camera is a=20 great tool used in our everyday predictive maintenance endeavors, = but it=20 can play tricks on our eyes if we do not investigate beyond what = we are=20 observing. Things truly are not always as they seem, here's an=20 example:

1) As indicated in the images below, we =93appear=94 to = have a hot spot=20 and differential in temperature on the =93C=94 phase of the = breaker, just to=20 the bottom of the actuator handle. (Remember to click all images = for a=20 larger view).

2) The operating parameters at the time of this visit = were as=20 follows:

Rating	200 amps
Loading	=93A=94 =96 8 amps	=93B=94 =96 48 amps	=93C=94 =96 24 amps
THD%C	=93A=94 =96 <2%	=93B=94 =96 <2%	=93C=94 =96 <2%
Millivolt Drop	=93A=94 =96 .001	=93B=94 =96 .001	=93C=94 =96=20 .001

Relatively normal operating conditions = in a=20 generally climate controlled room, with no evidence of any = reflective=20 source of infrared radiation noted.

3) So why is there a = temperature of=20 nearly 40=B0 C (104=B0 F for those who relate to Fahrenheit)? With = a high=20 emissivity on the breaker itself, reflective effects would need to = originate from a much higher heat source to have an effect on the = observed=20 actual temperature on the breaker.

4) How could the = operating parameters=20 be within guidelines, no apparent resistance increase was measured = across=20 the breaker contacts via milli-volt observation, harmonic = distortion=20 levels were deemed negligible, and the highest load demand on = =93B=94 phase=20 DID NOT have the highest temperature rise?

The answer to this was revealed when = the breaker=20 manufacturer, Cutler-Hammer, assisted in the dilemma resolution. = The=20 source of the heat was determined to be an under voltage relay = coil used=20 in conjunction with the electronic sensing and trip unit, mounted = under=20 the case at the location illustrated above. The heat associated = with=20 electromagnetic induction properties or transformers and coils = radiated to=20 the breaker case and were detected by the IR camera.

The unit = in question=20 is illustrated in the blow up view, showing this can be either = left or=20 right hand mount.

Below is = an assembled=20 view illustrating physical location of where =93heat=94 may be=20 observed.

Another good example is illustrated = below. A=20 transformer with balanced loading well below its rating, low = harmonic=20 content, and no extreme conditions present in the surrounding = environment=20 =93appears=94 to have a coil winding that has a temperature = difference of=20 nearly 10=B0 C between =93B=94 and =93C=94 phase windings, as = indicated by the=20 arrow. The =93B=94 phase winding was approximately 48=B0 C and the = =93C=94 phase was=20 approximately 41=B0 C.

Based on those operating parameters, = this is a=20 problem as defined by NETA guidelines that is near the = =93Severe=94 range as=20 related to our severity criteria levels. In fact, closer = quantitative=20 analysis of the thermogram reveals the reasons for the = =93apparent=94=20 differential temperature.

1) The =93B=94 phase winding does not = have the=20 volumetric area to allow for natural convection cooling of the = heat, thus=20 it cannot dissipate heat as efficiently.

2) The core = temperature is=20 much higher as compared to the windings and the heat generated in = this=20 area will influence the winding temperatures if its effects are = not=20 compensated for. This causes a radiating of heat to impinge on the = winding=20 and affect the observed temperature.

3) The actual measured = temperature=20 does not exceed the manufacturer specified guidelines with respect = to=20 temperature.

Again this example illustrates the = absolute need=20 to provide quantitative analysis of any =93apparent=94 thermal = anomalies.=20 Other surrounding factors had an effect on what we were observing = and they=20 had to be taken into consideration.

CONCLUSION

With the advent of solid-state = protection in=20 devices of this nature, this scenario is going to become more = common. We=20 cannot rely on what we see alone, and sometimes even the = analytical tools=20 at our disposal still fail to reveal the source of a = problem.

The first example aids in = demonstrating the=20 absolute need to utilize milli-volt drop tests with respect to = thermal=20 anomalies, as it will provide one of several methods in assisting = us to=20 prove or disprove the presence of an actual problem, by = effectively=20 measuring and quantifying the passive resistance of a contact = point using=20 Ohms law, and allowing us to calculate I^2 R losses. With the lack = of=20 voltage drop and harmonic currents in this problem, we can safely=20 determine the breaker contacts and terminations are suitable and = heating=20 is not related to non-linear loading.

To rely solely on temperature = difference from=20 similar components or ambient air is not enough for us to diagnose = a=20 problem such as this. Even the generalized guidelines in the NETA = specs=20 for electrical equipment cannot be relied upon as a rigid = benchmark in=20 this respect. If the NETA standards were applied in the above = example, it=20 would be approaching the =93Critical=94 level, as the = temperature=20 difference is compared to ambient is nearly 40=B0 C. Is the case = in the=20 first example? Would you recommend an immediate outage to service = this=20 component? Not likely with the operating conditions noted. In the = second=20 example, the untrained eye would most certainly identify this as a = problem=20 based solely on differential temperature guidelines.

We must use all of our tools to draw = accurate=20 conclusions, as many factors need to be taken into consideration = with=20 respect to these types of situations. We cannot just assume that = because a=20 certain temperature differential exists, apparent or true, = particularly=20 with respect to direct measurement, that a problem exists. Making=20 qualitative and quantitative analysis is key in keeping us one = step above=20 the rest. Sure a hot spot exists in these examples, but your eyes = can=20 deceive you if you do not give consideration to such variables as = external=20 influencing factors and load demands, and not provide proper = compensation=20 values to the camera for these factors.

Editor's=20 note: Joe receives an InfraMation Executive Attach=E9 for his = article=20 = contribution.