The ABCs Of Thermal Imaging

Nov. 1, 2000
Harvey Eisner asks the experts for information that firefighters need when safely using the latest thermal imaging technology on the fireground.
Firehouse® Magazine interviewed representatives from Safe-IR Inc. who are veteran firefighters from around the country providing thermal imaging training for the fire service. They have presented classroom and hands-on training at more than 800 fire departments in 47 states and in Canada for thousands of firefighters.

This question-and-answer session offers basic information that firefighters need to operate safely and effectively.

What is the benefit of using a thermal imager (TI)?

The technology is being marketed at the heartstrings - "If we had the TI, we would have made the rescue, we could have saved the child or the firefighter." If the TI does that once, it's worth its weight in gold.

For the day-to-day operations for the firefighter who is doing their job around the country, the biggest tactical advantage is to locate the seat of the fire quicker, monitoring the changes in thermal conditions as we are operating and accountability of firefighters.

Accountability is a major concern in the fire service today. Most departments have accountability systems in place. It's a tag we place on the rig, a riding list that the officer carries. Those seem to be popular types of accountability. In retrospect, it is a passive type. It doesn't tell us anything. If something happens to the individual or it is catastrophic where the building collapses or you have deteriorating fire conditions rapidly and you need a head count, then we go back to the rig and get those accountability lists or tags.

A TI operating inside that fire building provides a more proactive accountability. You are monitoring the firefighters where they are operating. If a member goes down, there is someone inside with visual accountability. As companies are changing from an aggressive interior operation to a defensive attack, we back out of the building. If the last person out is the one with a thermal imager, it might prevent that one firefighter from making a wrong turn and heading the wrong way. These are the types of things that a TI can provide when operating inside the building.

What about fire departments that don't have a lot of fire duty?

Five years ago, I met a volunteer fire chief in a rural area of northern Wisconsin. I asked the chief why he needed a TI. The chief said,"We get dairy barn fires. When we get smoldering hay inside the structure, the structure is not involved. The only way to save the structure is to get firefighters inside and physically move the hay." The chief said, "It has always been my fear that someone would go down in the smoky hay and we wouldn't have a clue about it. My idea with the thermal imager is to park a firefighter in the corner and watch to make sure the firefighters are safe while they are working. That's why I bought the TI."

Five years ago, a chief in northern Wisconsin worried about accountability. It's the same problem that's facing the fire service as we head into the millennium. I thought the chief was ahead of his time.

When do you turn the TI on?

As soon as you know you are going to use it. All the units have a warm-up time from 30 to 90 seconds. It gives you an opportunity to do a functional check of the unit to make sure it is operating properly. You can check on the battery power. Most units come with two batteries or a combination of a rechargeable and a shell where you can place regular batteries. Always place a spare battery pack in your pocket. The batteries are the weakest link. There are no user-serviceable parts in the TI. If the unit fails, the only recourse you have is to change the battery. If that doesn't work, you now have an extra five to seven pounds that you are carrying around.

How do you operate inside the fire building?

There are two different ways you can operate with a TI. You can lead the search or you can direct. If you lead the search, that puts the camera and the operator in front of the team he is working with. If you are leading with the TI, there is a tendency with some people to get caught up in the technology and take off and leave the team. You can lose the team concept.

This is an item that has to be stressed. By directing, you have your team out in front of you. It works well in smaller-type buildings, private dwellings and smaller rooms. Members may be doing conventional search techniques and the operation is providing accountability, monitoring conditions and directing firefighters to areas where the search needs to be concentrated.

The key to both is interpretation. You are doing no good to anyone and more harm if you don't have a clue as to what you are looking at.

As the technology changes, should the fire service keep abreast of it?

As the technology changes, the fire service really needs to keep abreast of it.

Many departments have one type of camera they have trained on and they are used to seeing things one way. Then when they go to another type of TI, they expect to see the same things and they are not there. Departments need to be aware of this when evaluating TIs. They have to form their own opinions. They have to educate themselves prior to purchasing. They have to understand in the fire service today, NFPA, NIOSH and OSHA aren't involved. There are no standards.

The manufacturers are setting the standards they think are important to sell TI for them. A lot of the fire service is buying TI the way they go to a department store and buy a television set. Stand there and look at which one has the prettiest picture. We are not taking into consideration the user friendliness, compatibility with your personal protective equipment and what the camera is going to look like or how it will perform under the worst conditions in a fire situation. Keep the training up to date with the product you are using.

How do you interpret the display comparing heat or flames?

You have to let the camera work for you. The basic concept of infrared imaging is that there has to be thermal contrast. If there is no contrast, the TI is not going to work. You wouldn't take a TI into a cave, everything is the same temperature.

Objects with different masses and densities absorb and give off energy at different rates. That's what gives us contrast. The more contrast there is, the better the TI is going to work. TIs like heat, that's when they perform their best. We look for changes in thermal contrast. Depending on the object, you get more definition in the image you are seeing.

You will see it before you feel it. If you pull up to a 40-foot ranch house at 2 A.M. and fire is blowing out the front bedroom windows, that's not much for the American fire service. One line in operation, down the hallway, a room and contents, and the fire is going out. If we go to the house next door, the very next night, it might be the same 40-foot ranch, but it is puffing ugly black smoke out of every nook and cranny. It is not the same fire we had last night. We don't have that visual indicator as to where is the fire. It might be in the same bedroom.

With the TI you have to look up at the ceiling to get an idea of the thermal conditions. You are going to see the convected gases moving. This is where the interpretation is a little different between cameras, manufacturers and technology. If the convected gases are moving toward us, it could mean the fire is in front of us. As we lower the TI down and take a look, we are going to see the greatest thermal contrast leading back to the room where the seat of the fire probably is. Day in and day out, that's what the TI is going to do for the American fire service.

Are there problems to be aware of?

Proper interpretation. If you don't know what you are looking at and how to interpret it and be reasonably proficient at it, you are going to get into trouble. It is easy to get overconfident. You can move too far too fast.

Sometimes our lack of visibility has kept us safe. You have to get down on your hands and knees. We may not have advanced as quickly because of the lack of visibility. This tool is going to give you your eyesight back. You have to be aware of your surroundings. You want to scan the area, take your reference points. In the past, that couch or bed weren't there until we felt them. Now you have visual indicators. It is real easy to get tunnel vision with a TI. You have a narrow field of view. You constantly have to be scanning.

Are there other potential uses of a TI?

You are limited only by your own imagination. Thermal imaging has been in the fire service since the 1980s. It wasn't until we were trained that we understood the full potential. Since 1987, until we were trained, we may have used the TI one to two times a year. Since training, we have used the camera monthly, weekly and now daily. Firefighters fight to use the camera each day at almost every operation. Other uses include outdoor search, hazardous material incidents and overhauling.

While overhauling a fire room, the entire room will look white. There are no guarantees. Look for the spots in the display that are whiter. The TI will help to prevent rekindles, but it doesn't replace the hook. You still have to open up. Be diligent. It is a quick way to get an idea of fire extension and travel but the TI doesn't replace sound overhauling procedures. The TI isn't the answer to manpower problems. It is just another tool.

What if the TI gets wet?

Try and avoid getting the TI wet. The potential for steam and condensation to affect the TI exists. Most of the new units are designed to operate in the environment we place them in. The condensation you get on your SCBA facemask you may get on the TI lens and display.

What should you be aware of in rapidly changing conditions?

How many times have you read in Firehouse® that firefighters entered a building that had a light smoke condition and they were searching for the seat of the smoke condition? All of a sudden, conditions changed and things go bad. That's not the time to look around and see where the door is. You should have done that before conditions changed.

Be aware of your surroundings. A previous student told us, "Everything you said could happen did happen at an incident our department responded to." There was a fire in a private dwelling. Two firefighters went in and found the door to the cellar, where the greatest amount of heat was venting. They made their way into the basement and the fire lit up. The first thing to go was the TI. It was hectic to get back out. They abandoned what they would have done in the past because they had this new technology. It almost cost them their lives.

Another firefighter said, "We had a drill with a smoke machine, it didn't go too well." Remember contrast; a dummy or mannequin has no real contrast if everything is the same temperature.

How do you utilize the TI to complete a secondary search?

The TI is not the answer to do a thorough secondary search. You still have to get down on your hands and knees and you have to go through the debris and get down to the floor.

What about future purchases?

The industry is changing as fast as the computer industry. There are no standards. You need a TI. Make a decision now, buy something. Learn how to use it properly. Let the tool work for you. The industry is going to evolve, change and get cheaper. Don't wait for the ultimate TI.

Can you describe a recent incident where the TI was used?

There was a fire in the basement of an electronics store. Inside the first floor, visibility was zero. Firefighters were visible through the TI very deep into the rear of the store. The TI picked up fire burning through the floor and extending to the walls behind the group of firefighters. The TI operator notified the group of firefighters of the fire behind them. He also requested a hand line to knock down the fire. He then radioed the incident commander to have the exposure checked for extension. Without the TI, there could have been trouble. A typical use of the TI.

How do we get more firefighters to use the TI?

Firefighters have to be involved and educated before the TI is purchased. They have to continue to educate themselves during the selection process and then have to educate themselves after they have made the selection.

Without some understanding of how the TI works, what it does and why it does what it does what it does for you, you are not going to use it. Firefighters are running around with the TI on the rig and that's exactly where they are staying. Firefighters are reluctant to use them. When they get frustrated at 3 A.M. when they can't find the odor of smoke, some guy says go get the TI. In five minutes the operation is completed. Proper interpretation of the pictorial representation of the temperature of everything in the room.

For further information, contact Safe-IR Inc. at 877-4-SAFEIR or

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