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Old 27-10-2013, 03:25 PM
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pvelez (Pete)
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Ice

My STX16803 seems to be icing up.

Have a look at the attached screenshot.

This is a 30 second light taken through the PW with the cover on. Binned x2 in L, there is enough light to take an image and see how the sensor window looks. To me, its pretty icy.

I took out the dessicant plug and baked it for 4 hours as instructed in the SBIG manual. Same result.

I ran the camera at 0C for about an hour last night and then dropped the cooling to -25C. It iced up in the same way as appears here. I left it running for another hour to see if it would clear on its own. An image taken after that hour is also attached.

Has anyone else experienced this? Is there a heater attached to the chamber cover that might not be working?

Next step is to contact SBIG but I thought I'd ask the gurus first.

Pete
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Old 27-10-2013, 03:36 PM
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Perhaps it takes some time to clear accumulated moisture.

Here is a screenshot after running the cooler for 20 minutes.

Will have another look in half an hour.

Pete
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Old 27-10-2013, 03:46 PM
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multiweb (Marc)
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You must have trapped moist air in the sensor chamber. Was it argon purged? If it was you can get an argon bottle from any welding shop and fill it in yourself. They retail at about $26.00 for a small canister.
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Old 27-10-2013, 03:49 PM
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Thanks Marc

I'm sure there is moist air there - I would hope that the dessicant would clear it. I guess the real test will be to see if all of the ice clears. Last night it just wouldn't clear around the edges.

Pete
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Old 27-10-2013, 04:37 PM
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One hour later...

Pete
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Old 27-10-2013, 08:29 PM
stevous67 (Steve M)
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Quote:
Originally Posted by pvelez View Post
One hour later...

Pete

I've seen that before, with my STL11k. Peter Ward purge the chamber and stuck another heater on the outer case. It was advised my cooling to ambient may be affected, but no it wasn't. I can cool all year round to -20 without an issue (-30 winter).

I did the same with the desiccant plug as you did, and there was no change to the frosting. Plus I tried pre-running the camera at zero to let the original heaters sink their heat in, but this did not help.

Make sure your O-ring to the plug is not damaged. You can replace these at plumbing stores.

You could try Marc's suggestion, but I was to scared to try this myself. Peter Wards service rectified my camera, and has worked now without issue for more than a year.

Good luck,

Steve
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Old 28-10-2013, 07:25 PM
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Thanks Steve

I've booked my camera in to see Dr Peter W early next week

Pete
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Old 29-10-2013, 09:44 AM
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Thanks Steve

I've booked my camera in to see Dr Peter W early next week

Pete
Good move. No matter how much dessicant you have in there and how much you bake it, if you have moist air trapped to start with it'll be very hard not to ice up. Purging is the way.
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