Seek Thermal Camera and a Motorola X smart phone. Photo by Bill Gabbert.
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 $200 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.
This photo of Unit #3 of the Cold Brook prescribed fire was taken four days after the IR image below, from approximately the same location. Unlike the other pairs of images this photo was taken with a different camera at a different time than the pairs of Seek Thermal IR/smart phone combination photos farther down.
An IR image of approximately the same area as the previous photo. This was taken October 23, 2014 with the Seek Thermal IR camera shortly after some of the area in the image had been ignited on the Cold Brook prescribed fire in Wind Cave National Park.
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.
Note the tree’s shadow, which had been shielded from the sun, and compare it to the same area in the IR version below. The photographer’s shadow on the lower-right had only been present for seconds, and had not yet affected the temperature of the ground.
IR version of the previous image. There was no visible smoke in this area. The image was taken at 3:02 p.m. MDT on a cloudless day. The air temperature, I believe, was in the 60s, but the sun heated many objects to around 100 F. The only area in this image that was still burning was the spot near the displayed temperature of +194 F.