Routine maintenance ensures that a thermal imager performs when needed and enjoys a long service life. This column focuses on operational checks and battery maintenance.
Certain tasks can be done daily, weekly and monthly to help maximize the performance of your thermal imager. Here are a few key areas that require attention:
• Inspect the window at the front of the imager (often referred to as a lens), display cover and operating buttons to be sure they are clear of obvious debris.
• Clean the window at the front of the imager as well as the display cover to remove any buildup of soot or residue as this will cause image deterioration. Check with your thermal imaging manufacturer as to what to use, but often simple soap and water will do the trick.
• Check the outer shell of the TI for cracks or misalignments of screws or mating surfaces that may let water enter.
• Ensure all exterior screws are tightened and all gaskets appear pliable and intact (UV exposure can cause gaskets to dry out and crack, so inspect closely).
• Check all other items and accessories for the TI to ensure proper fit and function, including handles, transmitters, hand straps and carrying straps.
Many departments, as part of the daily apparatus checks, turn the imager on to make sure it is operational, but simply turning the imager on, seeing if an image is displayed and then turning it off again offers no real assurance that all is OK. If you are going to perform an operational check of the thermal imager each morning, then you should really check how it operates.
• Turn it on and check the image quality and clarity.
• Does the temperature measurement respond? Does the color activate as expected? Does the imager shift from high gain to low gain appropriately? All three of these can be tested with a stove. If you have a gas stove, a frying pan helps the process along. Simply turn the stove on and check that all works as expected.
• Let the imager run for 30 minutes to an hour to see if the battery gauge is reliable.
• Activate all features such as digital zoom to make sure they are responsive.
Batteries are the most frequent cause of imager failure and customer complaints – the batteries don’t run long enough, don’t last long enough or don’t charge fast enough. Most of today’s fire apparatus are equipped with devices to maintain a charge on the apparatus battery. To maximize performance, develop a plan for maintaining, charging, storing and replacing TI batteries. Perform the following weekly:
• Verify that the batteries do not show physical signs of damage.
• Rotate the batteries in your imagers and charger units.
• Fully charge all of your batteries.
Perform the following monthly:
• Verify that the battery contacts on the batteries and the imagers are free of corrosion and that the battery chargers are corrosion free on all primary contacts
• If you are not actively using your TI for more than 30 minutes at least once per week, completely cycle each battery by doing the following: Fully charge the battery, then place it in the imager, and turn the imager on. Let the imager operate until there is no viewable image on the screen, then fully charge again.
• Ensure all batteries are properly charged and/or charging. Any regular rechargeable battery will normally lose a portion of its charge over a period of days and weeks. If a battery remains in discharge for an extended period, it may need to be exercised to restore it to optimal performance. To exercise a battery, follow the steps above for cycling batteries and repeat three to four times.
• Don’t leave the imager on after the battery has died. Some imagers will continue to drain power from the battery, even after the battery has died, resulting in a “deep discharge” state. Deep discharging will damage the battery cells and may cause the charger to falsely indicate a full charge on batteries that are damaged or will no longer hold a full charge.
• Be careful where you store your batteries. Prolonged storage of batteries in low- temperature (below 15 degrees Fahrenheit) or high-temperature environments (above 90°F) or near radiant heat sources may reduce battery capacity.
• Pay attention to the charger. Look for dirt or debris on or around the charging contacts. Check the power source for swelling or damage to the wire. (When working on the charger, always remove it from the power source for safety.)
BRAD HARVEY is the Thermal Imaging Product Manager at Bullard. He is a veteran of public safety as a firefighter, police officer and paramedic and is certified through the Law Enforcement Thermographers’ Association (LETA) as a thermal imaging instructor. Harvey has worked as a high-angle rescue instructor and is a certified rescue technician and fire instructor. If you have questions about thermal imaging, you may email him at firstname.lastname@example.org.