Magazine for the auto service professional
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18 | ASP February 2017 Technical Interpreting the image also takes practice. A thermal image looks very different from what we see in visible light. at's why most tools have an optical sensor and some way to compare the thermal image to the optical image. Most tools also provide more than one color palate because sometimes the detail shows more clearly in a black-and-white image. ey don't all work the same way, so switching from one tool to another requires a little practice, too. Finally, it also helps to use your imagination. For instance, sometimes it helps to start with everything at ambient temperature because the temperature difference you're looking for might be only ten degrees. ermal imagers are sensitive enough to detect that difference, and it's easier to see when everything else is at the same temperature. Like the scan tool and oscilloscope, a thermal imager gives you diagnostic speed and accu- racy, and in some cases it will show you things you can't see any other way. If you don't have one now, you probably will some day, because the capability it gives you is unique. Imagine how much better you can be at your chosen profession when you can see heat. Borescopes and inspection cameras Inspection cameras and borescopes have come a long way in recent years. Today you can buy a borescope for less than $15 that connects to an Android tablet or smartphone. Of course, you get what you pay for. Whether it's a camera or borescope, the most important features of the professional tools are camera size, camera articulation and image size. Tools designed for automotive work have a camera head that is less than 10 millimeters in diameter, and some are less than 6 mil- limeters. e lens is designed to produce high-definition close-up pictures, and it should also have some way to adjust the light level at the camera head. e best units have some method of articulating or rotating the camera head. While this feature puts the tool into a higher price category, it dramatically increases the tool's utility. When comparing these tools, pay attention to image capture or image resolution specifica- tions. It takes a high-resolution image sensor to capture a clear image of something that's only one inch from the lens. Most stand-alone inspection cameras and borescopes offer a photo-zoom feature, but images captured at 640 x 480 pixels will always be clearer than those captured at 320 x 240 pixels. It's not exactly X-ray vision, but inspection cameras, borescopes and thermal imagers give you the ability to see things you can't see any other way. With some imagination and a little practice, it will almost seem like you can see through walls. ese tools are not cheap, but the first time you confirm a clogged A/C condenser or retrieve a dropped bolt without removing the timing chain cover, you'll appre- ciate your investment. ■ Jacques Gordon has worked in the automotive industry for 40 years as a service technician, lab technician, trainer and technical writer. His began his writing career writing service manuals at Chilton Book Co. He currently holds ASE Master Technician and L1 certifications and has participated in ASE test writing workshops. If a picture is worth a thousand words, it can also save a lot of guesswork. Here's a picture of a cata- lytic converter taken with an inspection camera inserted through the oxygen sensor hole. The catalyst wasn't clogged and the only symptom was a catalyst efficiency code stored in the PCM. This picture not only helped the technician feel comfortable with his diagnosis, it also helped convince the otherwise skeptical customer of the need to buy a new catalytic converter. Photo courtesy of Junius