by Sal Mansfield
New River Industrial Communications, Ltd.

For the Auto Visual Inspection team (AVI) at Metronet Rail, the continual review of new techniques to improve the efficiency of the service it provides is a matter of policy. Thermography was added to its predictive maintenance arsenal in the late ‘90s and, as is typical of the technology, its application field has steadily broadened.

“We chose FLIR Systems infrared cameras based on their high level of flexibility to provide a good return on investment,” explained AVI Section Leader Joe Nolan. “Their use is growing with our experience.” And it’s not just the AVI unit that has benefited from the technology. Metronet colleagues responsible for electrical cabling and tunneling are now also using the cameras.

As part of Metronet’s Technical Services Team, the AVI Section provides instrumentation and testing expertise to support the company’s overall engineering functions. One of its key roles is to undertake track and track-train interface surveys using high tech custom video equipment. These surveys are conducted throughout the year on the nine lines in the network and also include train-borne thermal imaging cameras. For this purpose, the camera is mounted on the front of a train traveling at normal line speeds.

           
Poor electrical connections are readily apparent to the infrared thermography system

AVI does a concurrent visual and thermographic ‘sweep’ of the track network to reveal hot-spots that are then investigated in detail by the traction supply engineers who themselves have hand-held FLIR Systems infrared cameras. Prime targets are high voltage bonds, insulators and trackside switchgear. “Thermography adds an extra dimension to our survey facilities, allowing us to look at the track supply system,” explains Metronet AVI Systems Engineer, Salim Mohamed. “Additionally we are now using the technology to survey our rolling stock.”

For inspecting the integrity of electrical and mechanical systems on the underside of trains, infrared cameras are installed under the tracks. Monitoring is carried out during service hours without any disruption to the running schedules.

FLIR Systems has provided all the cameras currently in use at Metronet. AVI’s work is increasingly calling for real-time thermal imaging and digital output. For these applications the company invested in three, top-of-the-range ThermaCAM^® S-Series infrared cameras to supplement it’s professional P-Series models.

In line with all companies in this sector, Metronet’s contract is based on performance and quite simply any unnecessary service delay carries a cost penalty. Thermal imaging is part of a package of measures enabling the company to maintain the network infrastructure pro-actively and it is now seeking to develop its methods to grade the criticality of faults detected.

The collaboration between rolling stock, track, traction supply engineers and the AVI team is resulting in temperature thresholds being set for critical system elements, with each being assessed on its individual characteristics.

Service requirements are also being taken into account. “For example, we may set lower thresholds for the lines that serve central London,” Salim Mohamed explains. “Clearly more trains run on these traction circuits and there is a much higher cost implication in the event of failure.”

Next in line will be the development of Metronet’s data logging system to automate the survey process further. This work will result in the digitizing of its visual survey work initially. Thermal imaging will soon follow and by choosing FLIR Systems ThermaCAM^® S60, Metronet already has the hardware to support this development. This model is designed to provide 50Hz digital recording and evaluation of high-speed events. Its enhanced connectivity options include an IEEE-1394 FireWire interface for real-time transfer of fully radiometric 14-bit JPEG images and associated data.

Straight from the World Wide Web, here is what's going on in the world of infrared thermography.

• Course on the Theory and Practice of Infra Red Thermal Imaging in Medicine

• Earth and Moon through Rosetta’s eyes
  European Space Agency (ESA), World - May 3, 2005
  ... everything works fine at the final target,” said Angioletta Coradini, Principal Investigator for the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS ...

• 'Extinct' sable found in abandoned reserve
  Hindu, India - May 2, 2005
  ... But now an infrared camera installed by Angolan wildlife scientist Pedro Vaz Pinto has photographed a small herd of female sable. ...

• First exoplanet imaged
  Astronomy Magazine - Apr 30, 2005
  ... clinched the case. Glenn Schneider of the University of Arizona observed 2M1207b with Hubble's NICMOS infrared camera. In January ...

• The hot new way to detect breast cancer?
  Times Online, UK - Apr 26, 2005
  ... Thermography, or “digital thermal imaging”, uses an ultra-sensitive heat camera to pick up areas of the breast that are very slightly hotter than the ...

• Civilian-built spy aircraft monitors US southern border
  World Peace Herald, DC - Apr 24, 2005
  ... infrared camera. It is manually launched from a short runway and, once at a safe altitude, is switched to autopilot. Mr. King said the plane's thermal imaging ...

• Silhouette reveals hidden shape of star's envelope
  Spaceflight Now, FL - Apr 22, 2005
  ... Using the Infrared Camera and Spectrograph with Adaptive Optics on the Subaru telescope, the astronomers looked for candidates in and around the Omega Nebula ...

• NASA Creates 'Eye in the Sky' for Shuttle Chase Planes
  ScienceBlog.com - Apr 22, 2005
  ... housing. Marshall’s Mission Operations Laboratory helped develop software to control the infrared camera and recorder. Huntsville ...

• You can't hide your lying eyes from devices
  Indianapolis Star - Apr 17, 2005
  ... infrared camera detects a violet flaring of heat around her eyes, the telltale sign, researchers say, that she might be lying. Known as a thermal imaging device ...

• Local Kids Enter Science Contest with Thermomebear
  WISH, IN - Apr 11, 2005
  ... “It has a thermal imaging camera inside and it will like scan the whole room for any heat to tell what the temperature is,” said Bennett. ...

• Space tools gain healthy respect in home planet’s hospitals
  Fort Wayne Journal Gazette, IN - Apr 4, 2005
  ... reduced circulation of the blood, nerve damage and other health problems can result in abnormally hot or cold regions on the skin, and IR thermography is used ...

Here is a selection of recent new threads by IR Community members. Feel free to click the links, see how people have responded, and post your own response if you like.

• Safety cloths (PPE)
  Does anyone have guide lines they follow as to the type of clothing (PPE) to wear while they are making IR scans of energized, exposed high-voltage switchgear.
  Wearing all of the components to the Nomax suit for any length of time is a safety hazard in it self plus it makes using an IR camera imposable.

• infrared sightglass (hawk)
  I have recently bought 4 new hawk i.r.sightglass
  for our switch gear room, does anybody have thoughts on a good location to monitor I will be installing them on our next P.M. down time.

• Certifications
  How important and what benefits come from the 3 levels of IR certification? What would be a reasonable time frame to aquire these levels? I know it would depend on a number of unknowns, but I'd like some educated guesses if anyone would care to comment.

• Temperature Differences at Different Emissivities
  Assuming everything else is constant (reflected & ambient temperature, distance, etc.), is the temperature difference (delta T) between two points the same at different emissivities? I'm asking because if I'm only interested in temperature differences between two objects, I'd like to know how important it is to have the correct emissivity. I know the actual temperatures can vary unproportionally.

• Glass furnace Insulation Inspection?
  Is it possible to get accurate thermagraphic reading from a glass furnace that’s outside wall is constructed of steel and painted with aluminum paint? What is the emmissivity of aluminum paint?

• Sub-terrainian voids
  Has anyone had any experience with locating voids under concrete (aprox. 6-8 inches) using IR? If so, what parameters as far as temperature fluctuations are required and would you necessarily have to use an elevated platform or shoot from a roof?

• Wild 'testing' in high rise condo
  I have been asked by a local building contractor to submit a proposal to compliment his 'field test of windows and sliding glass doors' for a high rise condo now being built. They gave me AAMA's specifications for this test (It does not specify infrared). So I contacted the Tech people at AAMA who stated they did not have specifications for that type of test using infrared.
  Has anyone isolated an field test windows for moisture and air intrusion. Any leads, suggestions, etc. would be appreciated. Bernie2 at Internatioanl Imaging Tech

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

Brainteaser of the Month 

Here is this month's brainteaser. Readers who email us the correct identification and explanation of the thermal pattern in the thermogram are entered into a drawing to win a prize from ITC. Please put "Brainteaser" as the subject of the message.

Click here to email your guess

Do you have an interesting image that you think would challenge other thermographers? If so please email me your image (preferably in native .img, .jpg, .tif, .tgw, or .tmw format) with an accompanying visible photo and explanation. If your image is used, you receive a gift as well.

Last month's Brainteaser was a tough one; Daryl Androli explains his thermogram below:

"What looks like the sun over a hill or mountain is actually my thumb print on a frosted over window. The "ground effects" are created due to the ice formation on the window!"

But can you believe it? Buster Norris got it right on the money, incredible! Both receive an ITC low emissivity traveling coffee mug and a big thanks.

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