A thermal infrared (IR) camera that attaches to a smart phone is now available that could be useful for firefighters. The device, smaller than your thumb, connects to the USB or lightning plug on certain newer models of cell phones.
Everything (animals, humans, objects, water, etc.) emits infrared waves based on its temperature. An IR thermal camera measures these waves, which are invisible to human (or animal) eyes, and converts them into images.
We bought the new $250 Seek Thermal infrared camera to evaluate its effectiveness in helping wildland firefighters find lingering smoldering areas during the mopup stage of fire suppression. Under trees, organic material or duff can continue burning below the surface for days, weeks, or months and does not always produce smoke that can tip off a firefighter that the area needs attention. A still burning area that is missed can sometimes flare up and cause problems, possibly throwing burning embers across the fire line resulting in a slopover or spot fire with the potential to do serious damage.
Thermal cameras have traditionally been very expensive, which limited them to military and governmental applications. In the last ten years new, lower cost ($3,000-‐$5000+) industrial thermal cameras have emerged. They have been primarily used by police, firefighters, and contractors. Structural firefighters have used them to detect fires that are behind walls or ceilings. IR cameras can’t see through objects, but they can detect a wall, for example, that has been warmed by hidden combustion. A fire that is smoldering in deep duff in a wildfire will heat the surface of the ground, making it visible to an IR device.
Some of the wildland firefighters that have been around for a while might remember the thermal IR detector that looked like a flashlight. It had no viewing screen, but simply emitted a tone when heat was detected. I believe the pitch changed as the temperature increased. I don’t know if those are still being used. Does anyone remember what the cost of those was?
The Seek Thermal infrared camera can view long wave infrared (7.2 to 13 microns), has a resolution of 206 x 156 pixels, a 36-degree field of view, can detect temperatures between -40F (-40C) and +626F (+330C), and weighs 0.5 ounce.
At $200 the Seek Thermal infrared camera is far less expensive than other thermal infrared cameras. For example, FLIR makes many models of IR cameras. Their E4 has a resolution of 80 x 60 and sells for $995 at Amazon. The FLIR E5 with 120 x 90 resolution will set you back almost $1,500. The company recently developed the FLIR ONE, which like the Seek Thermal works with a smart phone, but is a much larger case-type design which fits entirely around the phone. It sells for $349, has a resolution of 80 x 60, and can only detect temperatures of 0 to 100C. The FLIR ONE will work with an iPhone with a lightning connector; there is no Android model.
The Seek Thermal is available in two versions: Android and IPhone. The Apple model is compatible with the iPhone 5, 5c, 5s, 6, and 6+ running iOS7 or iOS 8. The Android version will work with devices having microUSB connectors running Android version 4.3.1 (Jelly Bean) or later that support USB Host Mode (also called USB On The Go or OTG). The company says it has been tested extensively with the Galaxy S4 and S5 and the Moto G and X phones.
To use it, download the Seek Thermal app from the Apple app store or the Android Google Play store. I tested it on a Motorola X running Android 4.4.4. Helpfully, there were several prescribed fires being managed in Wind Cave National Park where I was able to find realistic conditions that wildland firefighters might run across.
The IR image above was taken about 800 feet from the prescribed fire.
The IR camera was set to display the maximum and minimum temperatures detected. Interestingly, the minimum is in the area of the sky, showing -2 F. The maximum is displayed as 189 F.
The IR camera can be set to show the following items on the image:
- Temperature in the middle of the image; (temperatures in Fahrenheit, Kelvin, or Celsius);
- Maximum and minimum temperatures anywhere in the image;
- Only areas that have a temperature within the min/max range that you set;
- No temperatures displayed;
- Date and time;
- Options for several different “color pallets” to represent temperatures;
- A watermark for Seek Thermal, which by default is turned on, unfortunately. But, it’s easy to turn off after cruising through the menus.
In addition, you can choose to display on the screen both the IR image and a true color “normal” image taken by your phone’s camera. You can drag a slider across to emphasize either.
You can take photos, of course, with the device. If you have the option selected for both regular and IR images, it will take and save two photos. If you have the temperatures displayed, they will also appear on the regular non-IR images.
Videos are also possible, as you can see below, in this two-second thermal infrared video of firefighters near a small area of burning grass on the Cold Brook prescribed fire in Wind Cave National Park, October 23, 2014. The firefighters were from the Alpine Hotshots, preparing to ignite the prescribed fire.
More examples of images are below, showing pairs of normal photos followed by the IR version of the same area.
The greater the difference in temperatures between the areas that are burning and everything else, the easier it will be to spot heat created by fires. That is why the U.S. Forest Service fixed wing IR planes fly and map fires at night, rather than during the day when the sun heats objects on the ground. I found that the displayed temperatures on the screen were more helpful than depending on the colors representing extreme heat.
The two images above were taken about 15 feet from three firefighters. They were not aware of this hot spot and even when I pointed toward it from 15 feet away they were not able to see it, since there was no smoke. After we walked over to the area and stood over it, they saw that it was hot, and mopped it up with scraping tools.
The single image below shows how the IR camera system got confused when the temperatures exceeded the range of the sensor, which is -40 F to +626 F. Often 6- and 7-digit positive and negative numbers were displayed when active fire was detected.
We used the IR thermal camera for a hour or so at a time and did not notice any major depletion of the battery, except when we turned on the location option where the lat/long would be displayed. This triggered the GPS into action, which can have a large effect on a battery. So if it is used extensively on a mopup shift, especially with lat/long turned on, there should be a way to either recharge or replace the battery, or simply transfer the camera to another phone. I can’t see a major need to have the location mode turned on while mopping up. But if you’re finding lightning fires or abandoned campfires from a helicopter, it would be extremely useful
As you can see in the list above, there are eight different “thermal modes”, depending on what you are imaging. Unfortunately, there is nothing even close to what you might run into on a wildland fire. We did not experiment with these modes, and just used the default “skin” mode while taking all of these photos. It is possible that other modes could work better on a wildfire.
We hope the developers will create a “vegetation” or “wildland fire” mode for the next revision of the app.
The company does not say anything about using the device on wildfires, but they list numerous other applications, including:
Safety and Security
- Scan the dark parking lot walking out to your car to see if there are any people (or animals) around.
- See what is making that noise in your back yard at night.
- See where the heat is leaking from your house and identify leaky windows, walls missing insulation, and other sources of energy loss.
- Trace water damage up a wall or across a ceiling to its source.
- Identify the location of clogs in pipes (just run hot water down the pipe and trace where it goes and stops).
- Ensure that there aren’t any other animals in the yard before letting your dog out at night.
- Find your dog or cat at night.
- See where on the counter or furniture your animal has been sleeping while you were out.
- Measure the heat distribution across your BBQ or griddle.
- Instantly measure the surface temperature of food.
- Measure level of propane in BBQ tank
- See structures and vessels on the water at night.
- Find objects/persons that fell overboard.
The camera displayed ridiculously wrong temperatures when very hot or flaming areas were imaged. But usually those areas are very obvious, and can be easily seen without any hand-held gadget. I was able to detect with the IR camera still burning areas that could not be found by a human, without them bending over, taking off their glove and holding the back of their hand just above the surface. Some of the areas found with the device could not even be detected with the back of the hand, unless the area was first stirred up with a scraping tool, to expose some of the hotter burning areas.
More real world experimentation by firefighters is needed, but this $200 gadget might make mopping up more efficient, and could result in fewer missed areas that need attention. It would be most useful near a fire line where it can be crucial to obtain 100 percent suppression.
Another use that could be explored is its effectiveness from a helicopter to detect a small lightning fire or abandoned campfire that would otherwise not be seen.
The Android version of the Seek Thermal IR camera can be purchased at Amazon.