Check the battery casing for damage. Damage such as cracks in the case can indicate a severe impact and may let dirt and debris get into the battery. More subtle damage such as swelling of the plastic can indicate a failure mode in the battery where the internal temperatures of the battery are getting too high during charging or use. All you will notice is that normally flat surfaces of the battery appear “domed.” This is different than external heat damage, which will normally appear bubbled or melted. Batteries that appear swollen should be removed from service because they can fail without warning.
Pay attention to the chargers as well. Look for dirt or debris on or around the charging contacts. Check the power source for the charger (wall adapter or vehicle plug) for signs of swelling or damage to the wire. Check the contacts of the charger and batteries for signs of corrosion or grime buildup. You can clean most battery contacts with something as simple as a pencil eraser. If it takes something more abrasive, a 220-grit sandpaper will also work. Be careful not to apply so much pressure that you damage the contacts. Never use steel wool as this can bridge the contacts of the battery or charger and cause serious damage. When working on the charger, you should always remove it from the power source for safety.
• Cleaning and inspecting – Inspect the outside of the imager for damage and cleanliness. Your thermal imager should always be kept as clean as possible. The shinier the surface of the imager, the more radiant heat the imager will reflect rather than absorb. Excessive soot buildup will lead to higher absorption of radiant heat and will affect how long the imager may run in an extremely hot environment.
Simple cleaning can be performed with soap and water. More stubborn stains can usually be safely cleaned with common, household cleaners or degreasers. You should never use straight bleach or hydrocarbon-based solvents on your thermal imager as these products may harm the thermoplastic housing or rubber seals. Always consult your owner’s manual or contact the manufacturer to check on recommended cleaning agents.
Once clean, the imager will be easier to inspect visually. When inspecting the imager, look for cracks in the plastic of the outer shell as well as any separation in external components. Also inspect all rubber or neoprene checking for pliability, crumbling, tears or other visible damage. Cracks, separations or damaged seals are common causes for water intrusion into the imager. Although all thermal imagers on the market today are IP67-rated (waterproof for 30-minute immersions in three feet of water) or better, this is only true when the imager leaves the factory. What happens after that is an issue of use and maintenance. There is nothing magic about the electronics of a thermal imager; there is magic only in the way they are protected from the harsh environment of firefighting. Water intrusion can lead to costly repairs, so frequent inspection is the best way to avoid this.
• Lenses, windows and display covers – An often-overlooked area of maintenance is the lens or window at the front of the imager. These areas can build up some very tough stains and will directly affect image quality. Most optics used in thermal imagers today are made of germanium. Germanium is a crystalline mineral that happens to be highly transparent to infrared energy. The germanium is often cooler than the firefighting environment because it has the internal air inside the imager behind it. This makes it susceptible to condensate from the environment resulting in buildup of soot and creosote. This buildup can reduce the amount of thermal energy getting into the imager, reducing overall picture quality as well as create a blurry appearance of the image. Cleaning this area of the imager can be extremely difficult. Contact the manufacturer for suitable cleaners and/or solvents. In some severe cases, replacement may be the only option.
Even though prices for thermal imagers have come down over recent years, they are still rather expensive pieces of equipment when compared to an axe or halligan tool. When a thermal imager breaks down, it can be both costly and inconvenient to repair. Although all imagers will eventually break down, the useful life can be extended and repairs avoided or minimized through a routine method of thorough inspection and immediate remediation of the small issues.