Thermal Imaging Manfred Kihn
We have seen a distinct trend toward lower-cost, smaller, lighter, and more capable thermal imagers (TI) in the fire service.
Quick advancements in technology cause the cost of that technology to fall, converting what was once unattainable into something that is now widely attainable. With higher deployment of new TI across units comes responsibility. The benefit of owning a TI relies solely on the training and interpretation of the operator.
We know that TIs are designed to process emitted infrared “heat signatures” and convert that information to an LCD screen to be interpreted by the operator. The cost, brand, resolution, or complexity of operation of a TI cannot overcome the strengths or weaknesses of the firefighter’s individual capability. A firefighter’s ability to quickly recognize a heat signature as normal/abnormal and know the TI’s reliance in all situations is the key factor to success.
Scenario 1: Atmospheric Attenuation
Recently, I talked with a captain who responded to a motor vehicle fire in a large underground parking garage. He experienced some perceived issues with the operation of the TI. They entered the structure, trying to determine the location of the vehicle, and were met with a wall of thick smoke. Using the TI was an added benefit until 13 of the structure’s sprinkler heads were automatically activated. This caused a loss of vision with the TI. The captain’s question to me was, Why did this happen? The answer is that the water particulate from the sprinkler system was dense enough to cause absorption of infrared energy from being detected or interpreted by the TI, rendering it ineffective for operation. The same effects can happen outside in heavy rain or snow or in extremely dense fog. This is called “Atmospheric Attenuation.”
Manual search procedures then went into effect, as they were unable to locate a standpipe and air management became a major concern; additional firefighting resources were brought in to control fire extinguishment. In this event, they relied heavily on their TI but quickly learned to revert to traditional search techniques.
Scenario 2: Thermal Saturation
A response to a water treatment pumphouse that showed light smoke challenged firefighters in this scenario. On investigation, the source location was condensed to a small but complex concrete mechanical room located within the structure. When firefighters made entry, they were confronted with a multitude of electrical panels, general wiring, pumps, and motors—all operating in close quarters while generating heat. This scenario created an environment bordering “Thermal Saturation.” This means that most or all the items in the field of view were close to or at the same temperature with little definition apparent on the TI screen.