Repairing a thermal imaging camera

[Mike] got his hands on this thermal imaging camera which is designed for use by Firefighters. As he’s demonstrating in the image above, it clips to a helmet and has a display what will let rescuers see through heavy smoke. But this one isn’t working right so he cracked it open and repaired the damaged board.

The hour-long video (embedded after the break) is quite interesting. He starts with a disassembly of the unit, before diving head-first into trouble shooting. There is a PCB inside that fills the entire U-shaped enclosure. The thermal sensor’s habit of cutting out seems to be a symptom of this design. There is one weak point where the board is very narrow. Flexing or vibrating that section will reset the sensor, and [Mike] ends up replacing a couple of components before the thing is fixed. These include a resistor and a ferrite bead both of which are suspected of having cracks due to that board flexing. The rest of the video is spent with an EEVblog-style look that the components and the construction.

[via Reddit]

Comments

  1. hboy007 says:

    I can confirm this is most likely a vacuum seal, I recently took apart a peltier cooled spectrometer camera and it too has a quenched pump stud with a rubber dipping. The manufacturer sells these with a 5 year warranty on the vacuum seal.
    Vacuum sealing is mainly used to avoid convective heat transfer and condensation.

  2. Drew says:

    Very, very cool stuff! I always wondered what was inside those things, but not have a few spare grand to buy one, I never thought I’d see their guts.

    Now, if only someone would post a DIY thermal imager, I could finally live my dream of having a HUD with Predator vision.

  3. Drew says:

    Possible, but I said DIY imager for a reason- passively cooled micro bolometers, the part that actually transcribes IR heat radition into readable data, are absurdly expensive. They’re the reason these things are thousands if not tens of thousands of dollars, and the resolution on them is low to boot.

    I really, really want a DIY thermal imager. I want Predator vision for airsoft games and deer hunting.

  4. John says:

    The best bit of this is the not-heatsinks. It’s something I’ve never thought about much, but when the air around you is hundreds of degrees, external heatsinking doesn’t do you much good.

  5. Attila says:

    … are absurdly expensive
    But why are they expensive? What’s the difference between what this camera does and any consumer camcorder with night vision mode? Consumer cameras also see IR, and they’re fairly cheap.

    • hboy007 says:

      consumer cameras use pixels directly integrated with the readout electronics in one chip. For 3-6µm it is still possible to create multiple quantum well structures made of III-V semiconductors (not silicon). Unfortunately, bipolar and MOS transistors are not very feasible in these material systems so for example you’d grow your epitaxial structure onto a GaAs wafer, isolate the pixels (etch trenches between them), bond a tile of the GaAs wafer onto a silicon CMOS readout chip and finally lift off the bulk. Think of it as an array of 320 x 240 blocks with 50x50x20µm size, each of which is soldered to a readout pixel location with several balls of solder.

      Of course I could have replied “the yield is low for these sensors” … ;-)

    • Drew says:

      They are absurdly expensive because of the spectrum they work in. They do not see the same range of IR that your camera does, and they see it with very high resolution in this area, capable of detecting range differences in very small amounts. The sensors are the main cost of these things, and they are incredibly expensive to produce.

      Those 2 things are why the imager is not the same as your camera with the IR filter removed. I wish it was that easy, but it’s not. And also, the camera cannot show the IR spectrum with color tint adjusted in real time for a given temperature range, and IR cameras can. They typically have several color modes, and a black and white mode. The black and white mode is usually what people spotters use- the military.

  6. Kris Lee says:

    This is pretty long video and it is quite high resolution camere he has.

    I liked the most the part where he shows various materials in front of the camera. Amazing that you could see through plastic bag with the thermal camera.

  7. SOI Sentinel says:

    Nice. This doesn’t have the same sensitivity, but I’ve been pushing for someone to carry them for a while:

    http://www.heimannsensor.com/products_imaging.php

    Yes, distributor costs (aka RAW value) for 100 units starts at around $100 for the 8×8 and goes up to $600 for the 32×31. But you could do live heat video via an 8 bit microcontroller.

  8. SOI Sentinel says:

    Nice. This doesn’t have the same sensitivity, but I’ve been pushing for someone to carry them for a while:

    http:(slash slash) http://www.heimannsensor.com (slash)products_imaging.php

    Yes, distributor costs (aka RAW value) for 100 units starts at around $100 for the 8×8 and goes up to $600 for the 32×31. But you could do live heat video via an 8 bit microcontroller.

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