Thermal imaging on your smartphone

The human eye can only see so much. Infrared vision—which shows your surroundings based on temperature—allows you to see in Predator-like rainbow hues. Though it is a cool technology, it is not new: Primitive night vision binoculars, after all, were one of the Allies’ great, secret weapons in World War II.

Flir, a Wilsonville, Oregon-based leader in the thermal imaging business since 1978, has provided essential gear to many high-stakes operations since then. When a space capsule docks with the International Space Station, Flir cameras are among its suite of tools that make the delicate operation possible. And it was a large, powerful Flir thermal camera that the Boston police department used to find one of the marathon bombers, thanks to his body heat glowing ghost-white as he hid beneath a tarp covering a trailered boat.

The Flir One ($199, around Rs12,700) and the Flir One Pro ($399), both announced on 6 June, aim to make this technology cheap, simple, and affordable enough for “therm-o-vision" to be an everyday tool. The dongle is about the size of a roll of Life Savers candy, and it attaches to the lightning port of a phone.

Both the regular and the Pro models are compatible with Apple and Android—the Android model has a USB C connector, and a mini USB version is due out later this year. Now in its third generation of the technology, the company has introduced smartwatch compatibility, so you can poke the camera into small openings and view its output on your wrist. Also new is a telescoping connector for a relatively snug fit, even with a case on your phone.

Most summer plans don’t include docking spaceships or hunting down terrorists. The real consumer value here is for do-it-yourself types who would like to find where, exactly, that window draft is coming from or which pipe is the really leaky one under the sink. Though you can’t see through walls as you would with an X-ray vision sense, you can see what’s going on beneath the surface.

For most home applications, the regular version of the Flir One will do the trick. It has an 80x60-pixel resolution thermal camera that can indicate temperatures from -4Fahrenheit (-20 Celsius) to 248Fahrenheit. The Pro can register temperatures as high as 752Fahrenheit on its 60x120-pixel thermal sensor, and it has access to a few more features on the app, such as the ability to display multiple spot temperature readings on screen. The second camera on both the regular and the Pro uses standard imaging to add visual detail to the infrared image. Both the regular and the Pro give about 40 minutes of use before needing to be recharged. You can get a bit more life if you use the only phone on the market with thermal imaging built in, the CAT S60.

Clogged or leaking pipes are often visible through drywall, and a faulty wire beneath the hood of your car will appear to glow. Cold air from gaps in a home’s insulation or from poorly installed windows become just as visible, as if it were water infiltrating—a valuable insight if found in a house you’re about to buy. And if you’ve ever had a pet bolt from the house as night fell, being able to spot the runaway by its heat signature as he hides in the bushes will get you something close to hero status.

Maybe the best part of the Flir One is being able to use it for decidedly non-heroic things. On a recent unseasonably sweltering spring day, I exercised my newfound thermal vision power in the quest for Truth, Justice, and the coldest Snapple in the refrigerator of my corner bodega.

As I scanned the bottles in the chilled case, the one at the very front of the cooler read as 41.2 degrees. The second bottle was about 40Fahrenheit. The third one, however? 39.2Fahrenheit, the coldest one in the entire row. Was it heroic? Nah. But it did make me feel just a bit more powerful.