Infrared Camera on Your Smart Phone: The Thermal Master P2 Pro
I’ll admit it. I’m obsessed with infrared cameras. Using them sort of makes you a superhero. You can see things that you wouldn’t otherwise be able to visualize. It’s just plain awesome (here are some examples of the things you can see).
When Thermal Master asked if I wanted to review their P2 Pro camera — I automatically said yes. So, there you have it. They sent me this nice (and tiny) infrared camera that just plugs into your iPhone (there’s an Android version also).
OK, you want to know about this camera? Let’s start with a very brief review of infrared light.
Crash Course in Infrared
Of course we have this thing we called visible light. This is an electromagnetic wave with wavelengths between 400 and 700 nanometers. Our eyes interpret the 700 nm light as the color red and 400 nm as violet (with the colors of the rainbow in between). Smaller wavelengths would be ultraviolet or x-rays. But for the longer wavelengths we have infrared.
Now let’s think about how we normally see things. If you have an apple in a room, you can’t see it unless you turn on a light. When you do, the light from the bulb hits the apple, reflects off it and then into your eye — you see the apple. But there’s a way other than reflect that we can see things — when the object produces its own light.
If you turn on your oven and let it get super hot, the oven element will be so hot that it glows. It emits a faint red light and you can see it without having the reflect some other light off it. The awesome part of this is that if you let the oven element cool off so you can’t see it — IT STILL EMITS electromagnetic waves. Oh, you can’t see these waves because they are not in the visible spectrum. Yes, they are mostly in the infrared region.
Here’s a super awesome simulation from PhET (they make some awesome physics sims). This shows that as an object cools down, two things happen. First, there is a lower intensity of EM radiation produced. Second, the peak wavelength increases as the temperature decreases.
This means that everything produces light — it’s just that the temperature of most of these things around you create light in the infrared and your eyes just don’t detect that.
But guess what? An infrared camera detects infrared light and then converts it into an image with different visible colors representing different infrared wavelengths. That way humans can essentially “see” in infrared. That’s why these infrared cameras give you super powers.
What about the thermal part? Well, since there is a relationship between wavelength and temperature, it’s sometimes possible to use the infrared light to measure the temperature of an object. However, there’s a problem. Let me use an infrared image as an example.
The picture shows two cans of juice — straight from the fridge so that they are the same temperature. However, if I use the thermal camera to measure the temperature (points P1 and P2) you can see that one is “warmer” than the other. The problem with the can on the left is that it’s doing two things. It’s both emitting infrared light because of its temperature AND it’s reflecting infrared light from its surroundings. We say that the can on the left has a low emissivity and the one on the right has a high emissivity.
OK, I think you know enough about infrared cameras so that we can talk about this particular camera.
Thermal Master P2 pro
Not too long ago, the cheapest infrared camera would be between 3,000 and 5,000 USD — and they weren’t even that good. But now you can buy something like the P2 pro for under 400 USD and it plugs right into your phone.
Let’s just get some of these details out of the way (that you could look up anyway). Some things about the P2 pro:
- It is indeed small. Thermal Master claims it’s the world’s smallest. I’ve only three other infrared cameras that connect to your phone and this is the smallest of them (but I haven’t tested THE WORLD).
- The camera has a resolution of 256 x 192 pixels. Yes, that seems low res — but pretty much all of the IR cameras are in that range. Trust me, the resolution is still high enough to give you super powered vision.
- The P2 pro can measure temperatures from -20 C to 600 C.
- The camera runs with phone based software called Temp Master. This probably is short for Temperature Master instead of a master that’s just temporary.
- Finally, the P2 pro includes a macro lens so that you can REALLY get close to some things for some interesting pictures.
Now for some other stuff. Let’s take a look at the app (Temp Master).
There’s a bunch of stuff here, but I’m just going to go over some of the more common features.
- Yes, you can measure temperature. As you can see above, there are 4 options for this: a point, line, box, or circle. The point just gives the estimated temperature at a point where the other options give the range of temperatures in that region. Yes, it is possible to change the temperature units as well as setting the emissivity value for the target.
- On the bottom row of options, you can see three circles that represents the color palette for the false colors. You can change this if you want, but the correct palatte is iron.
- The two box icon is to turn on the real image overlay. This will use the phone’s visible light camera to display a small window of what a normal (mere mortal) human would see.
- The slider is for more options and the camera icon allows you to capture images and videos.
Another surprisingly cool feature of the P2 pro is the inclusion of a macro lens.
This magnetically attaches to the front of the camera to change the focal length and allow you to get SUPER close to things. Here’s an image of a Raspberry Pi.
It seems like this could be used to find bad components on a circuit board — but that’s not something I’ve done before (but I will in the future).
Other Random Comments
- This thing is small. Quite small. That makes it easy to carry around, but it would be nice to have some type of small case for it so it doesn’t get messed up in my bag or pocket.
- Other IR cameras I have used had their own internal battery (so it had to be charged). The P2 pro doesn’t have a battery — just plug it in and go. That’s nice.
- The picture-in-picture feature is nice. It’s great to compare a visual image to a thermal image. Of course the phone’s visible camera and the P2 pro are some distance apart so that you see a difference perspective. Also, it would be nice to be able to adjust the visible camera image (zoom in) so that the framing is similar to the thermal camera — but it’s still great (especially for videos).
- The macro lens is so cool, it would be awesome to have a telephoto lens attachment too.
That’s about it. Let me know if you have any questions.
