In my preparations for a hopefully seamless and productive imaging during the dry season in winter, I thought of getting my QSI recharged with Argon, since I had the camera for over 4 years and the original Argon has most likely leaked away.
I was ready to ship the camera to QSI, but Vince from QSI confirmed that I could do it at home with one of those wine preservers that are used to create a layer of Argon on top of wine.
Refilling the camera's chamber was a fairly straightforward operation - gently released Argon directly into camera's chamber for about 30s. Now I have recharged desiccant and camera's chamber filled with Argon for $29.95 (plus electricity to bake desiccant for 4 hours at 260C), instead of spending in excess of $700 (shipping the camera to the UK plus service).
And on top of that, still have some Argon left for preserving opened wine bottles
I've been purging my QHY8 and QHY9 every single imaging session, then open them up and store them opened in sealed pelican cases with dessicant recharges. It works well. I use pure argon though from gasweld canisters. They're about $26.00. I'd be wary about anything else because of contamination.
Purging every imaging sessions seems to be a lot of work
According to the manual, Argon in a QSI camera should last about three years and after that they recommend baking the canister with desiccant every six or so months.
The one I've got is apparently pure without additives/contaminants, it is food grade and ISO9001 certified. Thank you for the hint with gasweld canisters but hopefully I wont need Argon for the next few years
I had no choice with the QHY8 as it's not really sealed. There's no chamber for the sensor. There is on in the QHY9 but I still purge the body of the camera. I do that with the nosepiece slightly unscrewed to let air through. Takes 30s to do.
I have used the Bunnings Argon canisters for purging my Canon 450D cooling system and camera internals. That particular camera operated inside a zip lock bag full of Argon, and worked very well.
I also have used the same gas to flood the sensor chamber in my ASI1600MM-C Version 1 camera. What I found was that putting the camera inside a plastic storage box and then putting the Argon in the box, was the risk free way of filling it up. Argon is heavier than air and will sit in a small box like a pond, so just submerge the camera to flood the compartment. I don't recommend pushing it into the camera compartment under pressure. Those dessicant pills have been known to shed dust. Obviously Chris, you would use a puffer bulb to blow out the chamber first and then check the sensor and cover glass closely before, and after filling, before buttoning it up.
Does the gas come out really fast from those wine argon cans? I'd be worried out anything in the camera getting dislodged and ending up on the sensor?
It was easy to control how fast Argon comes out, and even full flow was not that strong - no way anything would get dislodged, except for dust particles and water molecules that may be already inside your camera.
Some great advices from Marc and Glen, as I have no experience with QHY, ZWO nor modified dslr cameras
Excuse my ignorance here, but what's the benefits of putting Argon into these camera sensor chambers? Is it to drive out the oxygen out?
I guess I'm also surprised that for cameras like the ZWO that it would last long enough. Glen - how often did you have to redo the ASI1600?
I can only comment on the original Version 1 of the ASI1600MM-C, i do not know how they seal the later models. In Version 1s, the top compartment unscrews and the dessicant pills are inside that compartment held in four indentations spaced around the sensor. The top compartment has an O ring seal that it screws down against. The front sensor window (and I don't mean the sensor cover glass) also has a silicon sealing ring that the AR glass is held against by a screw down bezel.
I only ever flood the 1600 when I swap out the dessicant pills, and that might be once a year.
It is possible that the Argon may leak out due to atmospheric pressure variations over time, but the important thing is that there was no moisture trapped in the chamber when it was sealed. And truthfully the gas does not have to be Argon, any 'dry' gas, would work. Nitrogen is one, but not CO2 as it will transport moisture.
As far as I know Argon has lower thermal conductivity than air or Nitrogen, so it also helps in keeping the sensor colder (can reach a lower sensor temp with Argon) and perhaps to some extent Argon's lower thermal conductivity stops the cover window from fogging up. Nitrogen has very similar thermal conductivity as air, since air is mostly nitrogen anyway. Xenon has even lower thermal conductivity than Argon, but it is not commonly used perhaps due to a higher price or some other properties that I'm not aware of.
EDIT: just checked and FLI also uses Argon in their cameras, and offers Xenon as an option (extra cost).
Yes, I thought the main benefit was replacing room (with variable humidity) with very dry argon. I flush my QHY9 body as described by marc before extended mutli-night imaging sessions (e.g. astrofest). Most modern cameras are designed to avoid frosting of humidity with enclosed sensor chambers and/or mild heating around the front chamber glass.
However the QHY9 still rarely manages to get minor frosting on dust particles in my experience affecting flat correction etc. You can warm the camera, wait, then recool very slowly but not the sort of thing that is fun to be doing in the middle of a nice dark clear night
Peter has posted some good info on argon purging before and my chip in.
Thanks for the info. I think I've got the v2 of the ASI1600 and the seal, etc is the same as you described - I might give this a go as well and see what happens.
After many years of faithful problem free imaging, I started to notice a small amount of icing in one corner of the chip, so, given my current upgrade of mount etc in my observatory, I decided it was timely to have this beautiful camera serviced. Being rather reluctant to pull my (very expensive) PL16803 apart ... I sent her to FLI for their "Full Clean room Service" which includes:
Complete disassembly of camera
Removal of internal CCD PCBs (including seal board)
Process CCD related parts through moisture elimination
Clean and inspect seal areas
Replace CCD chamber o-rings and seals (both sides of seal board)
Ensure sensor surface is debris free
Clean camera window, replace camera window o-rings
Ensure integrity of TEC and thermistor connections
Replace internal desiccant
Replace corroded fins, fans/fan grids if required
Purge and back-fill chamber
Complete final test
Final image
Package and ship
The cost for this service is $550 plus shipping/insurance.
The tracking suggests I will have her back today or tomorrow ..EDIT it arrived today, Tues 5 March Halelulia! always nerve racking sending a such a costly item around the world for a service
Mike
Last edited by strongmanmike; 05-03-2019 at 04:31 PM.
After many years of faithful problem free imaging, I started to notice a small amount of icing in one corner of the chip, so, given my current upgrade of mount etc in my observatory, I decided it was timely to have this beautiful camera serviced. Being rather reluctant to pull my (very expensive) PL16803 apart ... I sent her to FLI for their "Full Clean room Service" which includes:
Complete disassembly of camera
Removal of internal CCD PCBs (including seal board)
Process CCD related parts through moisture elimination
Clean and inspect seal areas
Replace CCD chamber o-rings and seals (both sides of seal board)
Ensure sensor surface is debris free
Clean camera window, replace camera window o-rings
Ensure integrity of TEC and thermistor connections
Replace internal desiccant
Replace corroded fins, fans/fan grids if required
Purge and back-fill chamber
Complete final test
Final image
Package and ship
The cost for this service is $550 plus shipping/insurance.
The tracking suggests I will have her back today or tomorrow
I thought so My camera has window heaters and desiccant, so I must admit I was surprised when I started to see icing in one far corner, all be it only a small amount , regardless of the Argon leaking out..? I guess with no Argon and saturated desiccant, the heaters aren't quiiite enough on such a big chip..?
I thought so My camera has window heaters and desiccant, so I must admit I was surprised when I started to see icing in one far corner, all be it only a small amount , regardless of the Argon leaking out..? I guess with no Argon and saturated desiccant, the heaters aren't quiiite enough on such a big chip..?
Mike
Old age. Eventually moist always makes its way in no matter what. I had to purge the inner chamber of myQHY9 once as well in a plastic bag. Started on a corner as well. That's where the water droplets catch eventually.
Old age. Eventually moist always makes its way in no matter what. I had to purge the inner chamber of myQHY9 once as well in a plastic bag. Started on a corner as well. That's where the water droplets catch eventually.
Yep guessed as much ...anyway should be good for another several years now ..I recall Greg Terrance at FLI telling me the chamber should be good for about 7 years or so, I got about 9 years.
That's a very thorough service Mike. All bits all coming together - you must be very excited to start imaging again I myself can't wait for the dry season...in the meantime, there is always...
EDIT: 9 years! That's impressive. And it is still an ultimate sensor (and the camera) for any amateur astrophotographer. Here is to another 9 years of problem-free functioning of the camera!