The world of thermal imaging - Part 3

This is the last in a series of articles on the budding technology of infrared cameras.

At present, there are no less than a dozen different manufacturers of infrared camera technology. Each and every one of them offers a unique feature. The products not only appear different, but also offer different features that may or may not be a benefit to the end-user. For example, some of the imagers offer the ability to record voice along with the digital image file. This could be handy, but depending upon the application, may not necessarily be advantageous. For example, if you spend the majority of your time in noisy mechanical rooms, the recording may very well be inaudible.

Each manufacturer offers various screen pixel densities on their devices, which can affect the ability to perform detailed pixel diagnosis. Look carefully, and ask a lot of questions of the purveyor when making a decision to purchase, so that you don't purchase more or less camera than you really need.

In addition to pixel density, screen sizes vary as well. Having too small of a screen or low screen resolution will significantly affect the ability to perform field reviews when that becomes a necessary detail, such as determining the location of tubing prior to allowing holes to be drilled or cored through a radiantly heated surface. The core driller is usually standing by, with their equipment ready, waiting for people to get out of their way, so they can poke the hole and go to the next job.

Some manufacturers also offer the ability to perform real-time videos with cameras. While I don't really see a need for video capabilities in my field, I can see where it would be advantageous for certain industries (petroleum refining for example) where it would be advantageous to have real-time video recording capabilities. The cost associated with this particular feature can easily double or triple the cost of the imager. Again, one has to ask themselves, what do I intend to use this device for, and what features would be beneficial to myself and my customers in evaluating any given situation.

These devices are very complicated instruments with solid, state-of-the-art technology that requires attention to care. Different manufacturers offer various robustness of their devices with ability to handle shock from being dropped. My camera is rated to handle a fall from six feet. Not that I ever intend to drop it, but if that happened, the $5,000 instrument would turn into junk in a heart beat. This is something to consider in your purchasing decision, along with who will be using it, where will they be using it and under what conditions.

Most all imager manufacturers offer analysis software as a part of the imager package. I would recommend that you look extensively into this software and see exactly how good it really is. Some software is basically a filing system that allows you to store the images on your PC for reference at a later date. Some software allows you to perform a pixel-by-pixel analysis of surface temperatures and the ability to tag these individual points in either an actual temperature, or in some cases as a point number with a corresponding temperature color chart. I prefer the use of a temperature reading more than the colorization method because some people are color blind and can't make a good determination based on color alone.

In addition, some software allows you to convert the image from the analysis software file extension to a file extension that can be viewed with most conventional photograph review programs in a format that most computers recognizes, like JPEG or BMP formats. My imager also came with a professional report program based on Microsoft Word that will allow me to make an extremely professional looking presentation that incorporates the thermal images into the document.

As with any technical product, it is important that the operators of the equipment be trained as to the proper use of the product. Just generating a colorful image is only part of the process. Understanding what to look for and when is more important than the image itself. Most manufacturers offer courses to train and certify your employees on the products they provide. If not, there are many individual companies that offer training.

Lastly, each manufacturer offers devices with a certain range of temperature and adjustable emissivity capabilities. When I purchased mine, I didn't feel that there would be a need to see temperatures above 300ºF, nor did I see a need for having an adjustable emissivity capability. I then found myself in a situation where the range of my camera was exceeded. The visual graphics are still extremely helpful, but the surface temperatures were out of the range of the imager.

Here is a list of some infrared imager manufacturers:

• Fluke offers approximately eight different models.
• FLIR offers approximately seven different models for thermal imaging, and numerous other (gas) systems are available.
• RAZ-IR currently offers three models.
• SATIR six models, plus other applications.
• Palmer Instruments offers six models for thermal imaging.
• Compix offers two models available for thermal imaging.
• LumaSense Technologies offers three models for thermal imaging.

Mark Eatherton is a Denver-based hydronics contractor. He can be reached via e-mail at [email protected] or by phone at 303-936-7606.

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