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  1. I need a CCD camera that can be used inside vacuum. Not the flange mounted types used in XUV-X-ray applications, but small compact preferably less than 20 mm dia housing. Does anyone have experience in using standard CCD cameras in vacuum, or can anyone suggest possible sources/references?

  2. Is it possible to set electronic exposure (aka electronic shutter) time, remotely through software, in a USB based CCD camera?

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1 Answer 1

I don't see too many issues using a standard USB camera in a vacuum. Your two largest issues are likely to be heat dissipation, and outgassing from the camera components.

Depending on how high a vacuum you need, you may need to package the camera in a hermetic container. There is almost inevitably going to be at least a small amount of soldering flux/VOCs left on the PCBs from production, and it will outgas when you pump the system down.
If you have sufficient pump capacity, or don't need extremely high vacuum, it shouldn't be too much trouble.
You could also try removing all the plastic from the camera, and baking the PCB assembly at a low temperature to speed up the out-gassing (~100°C?).

Second, at least some of the USB-cameras I have used do dissipate a fair amount of power, so depending on the camera, you may have localized heating issues due to the lack of convection cooling. It should be possible to deal with this using proper heat-strapping, though I think it would probably better to just pick a device with low dissipation.

Lastly, you can certainly buy some pretty interesting USB cameras, which do support all sorts of fun things like variable ISO, and variable shutter time. It mostly depends on your budget.


If you don't mind experimenting, I would say go to your local electronics store, and just buy a webcam, and see what happens (and post pictures!).

The hardest part, I think, is probably going to be hermetically sealing the cable feed-through. You can't just stick the cable in a cable gland, as you will get leakage through the cable, both between the strands, and between the individual wires and the sheath. You will need hermetically rated bulkhead connectors.

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Regarding outgassing, any component which contains gas and is tightly sealed and whose walls cannot hold the pressure will simply burst. Capacitors come to mind, but I wonder whether integrated circuits contain gaseous voids? Probably. I'd be concerned about batteries. –  Kaz Nov 16 '12 at 22:48
    
@Kaz - You'd be surprised how well most common components handle even high vacuum. I've put whole computers (admittedly a ultra-low-power AMD Geode based system, but anyways) in vacuum before. The main concern there is hard-disks, the heads of which require air for normal operation. Everything else works fine, you just need to worry about heat dissipation. –  Connor Wolf Nov 16 '12 at 23:01
    
I actually even tested some lithium pouch-cells in vacuum once. They looked like little balloons when you pull a vacuum on them, but they didn't rupture. I wouldn't trust them to maintain their capacity afterwards, though. –  Connor Wolf Nov 16 '12 at 23:03

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