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Old 14-07-2013, 05:47 PM
Hans Tucker (Hans)
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To Gas or Not To Gas

I notice that ATS offers a CCD Sensor Cleaning Service which also involves filling the sensor chamber with Argon gas which, according to the narrative, is to extend the life of the dessicant. Is there any other advantages to charging the chamber with Argon gas. Would it stop fogging of window during an imaging session.

Contemplating this service for my ST-8300M.
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Old 14-07-2013, 05:52 PM
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I notice that ATS offers a CCD Sensor Cleaning Service which also involves filling the sensor chamber with Argon gas which, according to the narrative, is to extend the life of the dessicant. Is there any other advantages to charging the chamber with Argon gas. Would it stop fogging of window during an imaging session.

Contemplating this service for my ST-8300M.
Yes. I got an Argon bottle from gasweld in Campbeltown for $26.00 and I purge my QHY8 with it. Works a treat. No dew.
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Old 14-07-2013, 06:12 PM
Hans Tucker (Hans)
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Yes. I got an Argon bottle from gasweld in Campbeltown for $26.00 and I purge my QHY8 with it. Works a treat. No dew.
Thanks Marc. Do you have to purge the chamber often? Is it a difficult process that requires special adapters?
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Old 14-07-2013, 06:33 PM
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should point out that ATS does not argon fill STF or ST402 type camera heads (really difficult/ nigh impossible to do)....having just serviced a ST402 (Jase???? anytime would be good )....

ATS uses ultra high purity BOC gas (probably worth Google-ing )

Only legacy ST, STT and STX cameras can avail themselves of this service.

Regards
Peter
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Old 14-07-2013, 07:36 PM
jase (Jason)
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...having just serviced a ST402 (Jase???? anytime would be good )....
Yep, you did a great job too Peter. The ST402 is operating flawlessly following its servicing mission. Its just like a bought one now.
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Old 15-07-2013, 07:54 AM
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Thanks Marc. Do you have to purge the chamber often? Is it a difficult process that requires special adapters?
Just a normal tap with a soft clip-on hose. You don't need any pressure or manifold set up. (see pics)

I do it every time I image. I put the nose piece on the camera and remove the rubber plug on the side then stick the hose in there and let it run for 15s then plug. Done.

It lasts until I open the camera again and store it dry and open in a sealed pelican case.

If you want to do a more permanent thing like a proper sealed chamber you get the camera in a sealed plastic back, fill it with argon, open the chamber then reseal it while still in the bag. That's it.

I use it for my QHY8 as a quicky on the field when it's very wet. That garantees I don't get annoying fogging whatsoever. I've had the same bottle for over a year now.
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Old 15-07-2013, 12:21 PM
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Marc,
I am getting a second hand QHY8 tomorrow so from what I have read about misting problems I am interested. When you insert the tube what orientation do you have the rubber plug hole, is Argon heavier or lighter than air? I notice from the instructions on the gas bottle label it says "don't let the contents escape to the atmosphere". Is this an issue? I am thinking it would be hard to weld without having it escape. Is the tap fitting available from BOG or Gasweld? From the label I take it that it is an outright purchase on the cylinder not a rental.
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Old 15-07-2013, 01:57 PM
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Marc,
I am getting a second hand QHY8 tomorrow so from what I have read about misting problems I am interested.
Hi Roger, make sure you silicon around the power, s-Video and USB ports to make it air tight. I also gaffer taped the body. It comes into two alu clam shells. Tape the seam.

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When you insert the tube what orientation do you have the rubber plug hole, is Argon heavier or lighter than air?
Yes it is heavier. Shove the hose in on the side (top). I use a paper tissue for etancheity. Body orientation... like when you fill a cuppa I guess. Fill from the top. Let it purge from the bottom.

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I notice from the instructions on the gas bottle label it says "don't let the contents escape to the atmosphere". Is this an issue? I am thinking it would be hard to weld without having it escape.
Unscrew the nosepiece slightly so the stale air comes out. As I said 15s max with a good flow so you get circulation. You can hear it. Screw nosepiece then replug hole with rubber. Good enough.

Refrigeration gases such as R-22/11/12 etc... are thightly regulated and I know by law installers have to purge large units and account for all the gas minus leaks when they discard ducted systems, etc... We're talking about large quantities. What you pump in your camera is minimal. Also argon welding releases some of the gas as well when the arc goes off and you still need to run the gas until the weld goes from red to cold or you'll get corrosion.

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Is the tap fitting available from BOG or Gasweld? From the label I take it that it is an outright purchase on the cylinder not a rental.
Yes. I bought it at the same place I got the canister from. Outright purchase yes. $26.00. WHen I'm done with it I'll probably take the bottle back and buiy a new one. I think they must be recycling them or dispose of them somehow.
Shop's here. Product's here.
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Old 15-07-2013, 06:34 PM
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Thanks for all that Marc, i'll give it a go
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Old 15-07-2013, 08:14 PM
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Makes me glad I use ICP-MS instruments at work. Analytical grade BOC argon on tap!
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Old 15-07-2013, 08:24 PM
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Ours are plumbed in a closed system Peter
So near and so far - 2 large PLCs of pure argon nearby!

What do you measure on the ICPs by the way?
Hmm, I suppose I could use the PLC bleed valves - what do you transport it in?
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Old 16-07-2013, 04:19 PM
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Ours are plumbed in a closed system Peter
So near and so far - 2 large PLCs of pure argon nearby!

What do you measure on the ICPs by the way?
Hmm, I suppose I could use the PLC bleed valves - what do you transport it in?
Thats no good! yes I used the bleed valve on ours and i didn't transport it in anything I took the camera to work. I have actually changed my setup now and am operating without the optical window so it is not purged anymore. I am yet to see if running without the window causes any detriment at all.

Might throw a pic up of my cam now as it is too cloudy to take a picture with it yet. It now goes MPCC > tsoag9 > filterwheel > Precise parts spacer > camera.

Also I measure anything and everything on the ICP's, we have 10 ICPOES and 5 ICPMS instruments that are mainly used for geological samples. Its a terrible job but it pays for more gear! Would love to find my way into a new lab but in Adelaide at the moment there are no jobs going in the science industry. I applied at SA water and they got back to me saying that the app process would take a while because they had 120 people on the long list.
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Old 17-07-2013, 04:36 AM
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I notice from the instructions on the gas bottle label it says "don't let the contents escape to the atmosphere". Is this an issue?
Argon is the third most common gas in the Earth's atmosphere after nitrogen and oxygen. Surprising to most people, who generally put carbon dioxide in this position http://mistupid.com/chemistry/aircomp.htm . You are unlikely to cause a catastrophe with any amount you are likely to use, especially since commercial argon is produced by extracting it from the Earth's atmosphere in the first place.
Geoff

Last edited by Geoff45; 17-07-2013 at 12:47 PM.
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Old 17-07-2013, 01:12 PM
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Yes, thanks Geoff, I thought not, I guess the concern is just releasing it in a close room and causing asphyxiation.

Not a worry, camera arrived, off to Gasweld this afternoon to get supplies just in case I every see a clear sky again
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Old 17-07-2013, 01:18 PM
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Yes, thanks Geoff, I thought not, I guess the concern is just releasing it in a close room and causing asphyxiation.
Nah... I had a wiff and it's ok... I think... I can't remember.
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