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Filling laser optics with nitrogen gas

steve001

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Hi, i didn't know all that was required to fill it with nitrogen gas. I tought getting the gas, getting a ziplock back and fill it up and screw the lens on there and trapping nitrogen in there while the bag was closed. Air couldn't escape from the cavity. The sealing is hard and the 3 element lens is sealed with strong thin adhesive cut precisely at the diameter of the lens and rim. which is pressed in place with the retainer ring. The diode is epoxied where the 3 cutouts are on the diode substrate and sealed around the module and the diode can with sealing gel i got from an electrician/boiler mechanic. I sealed everything my self. Threads are sealed to with a ton of teflon and the gel at the end when its focused to infinity. There is no way air could escape. Maybe after 6 years but absolutely not now

It could easily handle presure diferential, it could handle vacuum too for a long time. Altough i don't want it be vacuum as it puts more unnecessary strain. I tough you meant facuuming it and then seal it



Hi, i tried a ziplock bag and a desiccant bag. By drying the air inside and then sealing it off while dry air is inside. Altough, do you know how long it takes to dry air inside a nearly flattened ziplock back? I think this is by far the best way to get dry air inside my 100mm long pointer.

I also want to use this as laser sight for airsoft soon, i can't have it to condensate. The humidity here is terrible


Anyways both thanks for the inputs!
I don't think you are explaining problem accurately. Is this item seal or not?
 
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BlackOps

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I don't think you are explaining problem accurately. Is this item seal?
This item is sealed yes. But there is no way putting any gasses inside without unscrewing the lens. But i solved the problem!

Pictures of the lens and the host after it went in the freezer for a solid 5 min. No condensation inside and beam quality is perfect but as soon as i turn it on, the front of the lens condenses a bit but that is easily wiped off. I'm happy now. The host also condenses if i slightly blow at it, (last picture) thats how cold it is

Anyways thanks for the help! I will test in the car tomorrow as it tends to condense like hell in there


Edit: i fixed this by putting it in a nearly flattened dust free ziplock bag with a silica gel package right next to the open lens cavity and reassembled it a couple hours later inside the bag. Worked out awesome
 

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steve001

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This item is sealed yes. But there is no way putting any gasses inside without unscrewing the lens. But i solved the problem!

Pictures of the lens and the host after it went in the freezer for a solid 5 min. No condensation inside and beam quality is perfect but as soon as i turn it on, the front of the lens condenses a bit but that is easily wiped off. I'm happy now. The host also condenses if i slightly blow at it, (last picture) thats how cold it is

Anyways thanks for the help! I will test in the car tomorrow as it tends to condense like hell in there


Edit: i fixed this by putting it in a nearly flattened dust free ziplock bag with a silica gel package right next to the open lens cavity and reassembled it a couple hours later inside the bag. Worked out awesome
So it was never actually permanently sealed. Oy yey.
 

Cyparagon

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Nitrogen gas is dry, it is non hygroscopic. It couldn't absorb moisture.






Wow. Wow, it's not often I see someone state a falsehood as fact SO BOLDLY.

Nitrogen absorbs moisture like any other gas. It may surprise you to know that 78% of the material you're breathing right now is nitrogen. Do you suppose all the water vapor in the air magically avoids the nitrogen and hangs around the oxygen? Laughable.

Use a desiccant. I'm not sure where you got the idea that you need to stuff a bag into the optical cavity, but that's not right. You can either dry the air before, or stick a tiny grain in afterwards. In case it wasn't obvious, you do not need a large amount of material to dry a few cubic mm of air.
 

BlackOps

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Wow. Wow, it's not often I see someone state a falsehood as fact SO BOLDLY.

Nitrogen absorbs moisture like any other gas. It may surprise you to know that 78% of the material you're breathing right now is nitrogen. Do you suppose all the water vapor in the air magically avoids the nitrogen and hangs around the oxygen? Laughable.

Use a desiccant. I'm not sure where you got the idea that you need to stuff a bag into the optical cavity, but that's not right. You can either dry the air before, or stick a tiny grain in afterwards. In case it wasn't obvious, you do not need a large amount of material to dry a few cubic mm of air.
Sorry for the mis information. From what i've heard on the internet is that nitrogen gas is hygroscopic and doesn't absorb moisture. I was more interested to getting that stuff in the optics

I put the laser with the lens unscrewed inside the bag with a desiccant package in there and Screwed the lens on there while its in there and sealed. I had no other way of getting dry air as far as i know of. A grain would be flopping around in there. Either way it didn't condensate in a freezer while it first condensed in a car. Yet have to test that in the car but seeing from now i don't think it would condense.


Also, with the bag inside the cavity, i said that in case you tought i meant a lab laser or a big laser with a good amout of space in there, like placing it behind a bracket or something
 

Cyparagon

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A grain would be flopping around in there.



If only there was a substance that could fasten one thing to another thing. A substance that could... I don't know... "glue" it in place. Too bad no such substance exists. What a shame.


Surely your basic-problem-solving skills could find another way around it ;)
 

BlackOps

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If only there was a substance that could fasten one thing to another thing. A substance that could... I don't know... "glue" it in place. Too bad no such substance exists. What a shame.


Surely your basic-problem-solving skills could find another way around it ;)
I will show you how the cavity looks like later this day, glueing is no option. Its either making a bracket or forget it. I already put a glass piece coated for 405nm in there to prevent unwanted stuff to get on the diode window. This thing also would be on a airsoft and a real gun for the sight, i like to use brackets rather then the gettho style glue haha
 




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