Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Binoculars

Pages: 1 | 2 | 3 | 4 | (show all)
rocket_pc
newbie


Reged: 01/24/13

Nitrogen filled verses non-nitrogen binos
      #5641818 - 01/25/13 12:58 AM

Hi, I am newly subbed to Cloudy Nights. I already have a subject to ask about.

I am interested in purchasing a new pair of binoculars. I am trying to decide between a pair of binoculars that are nitrogen filled (fog resistent) (for example, the Nikon Action Extreme 10x50) and non-nitrogen filled binoculars (For example the Orion 15x70). The main concern I have about the nitrogen filled feature is that I wonder if the nitrogen can be discharged by impact (while in luggage that has been handled roughly for example) or gradually leak over time. I think of vacuum aluminum thermos bottles that never keep their pressure. I could get non-nitrogen binos with much higher magnification for almost half the price of nitrogen filled binos.

Thank you for your time on this subject.

D.


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: rocket_pc]
      #5641826 - 01/25/13 01:05 AM

Magnification has nothing to do with quality and nitrogen only prevents fogging on the inside. However, if the bino is sealed well enough to hold the nitrogen IN, it is sealed well enough to keep the moisture OUT.

Just a thought.

Welcome.

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jon Isaacs
Postmaster
*****

Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Nitrogen filled verses non-nitrogen binos new [Re: rocket_pc]
      #5641999 - 01/25/13 06:51 AM

Quote:

I could get non-nitrogen binos with much higher magnification for almost half the price of nitrogen filled binos.




First let me say Hello and Welcome to Cloudy Nights..

A few thoughts:

- Good binoculars cost money. There are plenty of high quality binoculars that are not nitrogen or argon sealed. Generally binoculars are rated by objective size and then magnification.

- The 10x50 action extremes are rugged, well made binoculars that one can expect to last a life time. The 15x70 Skywatchers are "budget/cheap" binoculars that some find acceptable but typically they have alignment/collimation problems.

Jon


Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5642177 - 01/25/13 09:31 AM

Quote:

Magnification has nothing to do with quality and nitrogen only prevents fogging on the inside. However, if the bino is sealed well enough to hold the nitrogen IN, it is sealed well enough to keep the moisture OUT.

Just a thought.

Welcome.

BillC




OK, former gas chemist here; in the lab for about 13 years. Nitrogen filling of anything is a gimic. Over time, and not that long a time, gases of ANY type permeate through a membrane (including glues, rubber o-rings, etc) in a manner to equalize the partial pressure of the gasses on either side of the membrane. So even if you start out with 0 psia of oxygen on one side of the membrane, over time you will inevitably end up with 2.94 psia oxygen (about 21 vol%) on that side, just like air. The same goes for moisture, except that moisture content in air is quite variable, so the partial pressure of H2O outside of the binocs waxes and wanes, changing the amount of pressure exerted on the membrane. So the best way to keep moisture OUT of the binocs is to store them in a dry environment...if moisture is a problem where you live, use one of those little silica gel packets inside your binoc case...and replace it regularly, since sooner or later it will become saturated with water and no longer absorb.

Now, the highlighted portion of Bill's quote above is true, if they are well-sealed, during any given observing session the ingress of enough moisture to fog the inside surfaces is unlikely.

Edited by bierbelly (01/25/13 09:33 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Binojunky
Carpal Tunnel
*****

Reged: 12/25/10

Re: Nitrogen filled verses non-nitrogen binos new [Re: bierbelly]
      #5642399 - 01/25/13 11:41 AM

For the longivity of any binocular keeping it free of moisture is preferable to keeping it wet, irrespective of the claims and specs.
However in a situation were the wet is unavoidable say search and rescue, coast guard and naval use then its worth noteing that they buy the very best available for that particular enviroment,DA.


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5642554 - 01/25/13 01:09 PM

Okay, you bloody “chemist here; in a lab for about 13 years,” you can consider that STOLEN for that book I’ve been whining about!!!

More on “nitrogen”:

The nitrogen is not there to pressurize the bino, as many suppose; it is there in case there should be any moisture left inside at the factory. Fungus can’t grow in an inert gas environment. [Sorry Tom, I can’t think of the real word I’m looking for and “inert” is what most people use anyway; help me out here.]

The marine Fujis, Swift Seahawk and Storm King, Tamaya BIFR and the like are REALLY sealed well. They are used in a cold, wet environment and need to be.
For the first few years at Captain’s I purged all such binos as part of the repair. Later, as costs rose, some wanted that process curtailed. NONE, of the many binos that were not purged after that EVER came back due to condensation! NONE! They’re either sealed or they’re not. To me that paints a pretty good picture.

As for the cheap products that profess to be “nitrogen filled,” that gimmick ranks right up there with showing a plastic, center-focus, ZOOM binocular and labeling it with the word “Military,” because they know that word gives the slow of thought shivers!

Oh, yeah it’s military, all right; the Lichtenstein submarine force just bought 3 last week! Basically, they're chum for a plastic eating shark!

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
Walt9129
member


Reged: 03/10/07

Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5642559 - 01/25/13 01:10 PM

bierbelly is right. Where I live I have lots of problems related to fungus. Of course, I use generous quantities of silica gel packets, keep my binoculars and telescopes open (no covers), open windows + solar light (not directly of course). That's one of the main aspects (fungus) to choose waterproof/Ni filled binoculars. Nothing lasts forever. So, silica gel and the procedures related above, IMO will be always mandatory.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Binojunky
Carpal Tunnel
*****

Reged: 12/25/10

Re: Nitrogen filled verses non-nitrogen binos new [Re: Walt9129]
      #5642603 - 01/25/13 01:30 PM

Bill C you warm the cockles of my heart, if I stole anything from your book its a coincidence and a apology is offered,however it seems to me that if you want premium wet weather performance then plonk the loot down and go for a Fuji,DA.

Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5642645 - 01/25/13 01:52 PM

But, if you look hard enough, you can find a waterproof, 140-power, 3-ounce, center-focus, ZOOM binocular for $7.15! . . . 'That's perfectly collimated!

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5642717 - 01/25/13 02:31 PM

Quote:

Okay, you bloody “chemist here; in a lab for about 13 years,” you can consider that STOLEN for that book I’ve been whining about!!!

More on “nitrogen”:

The nitrogen is not there to pressurize the bino, as many suppose; it is there in case there should be any moisture left inside at the factory. Fungus can’t grow in an inert gas environment. [Sorry Tom, I can’t think of the real word I’m looking for and “inert” is what most people use anyway; help me out here.]

BillC




I think the term "inert" when applied to nitrogen is appropriate. Nitrogen gas (N2) is only reactive under very high temperatures and pressures, so while it's not classified as an "inert" element according to the periodic table, in its normal gaseous state, it is all but inert.


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: bierbelly]
      #5642855 - 01/25/13 03:53 PM

I was looking for what it is REALLY classified as, but didn't have time to look it up.

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
Brent
sage
*****

Reged: 11/18/04

Loc: NE Missouri
Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5643055 - 01/25/13 05:51 PM

Quote:

I was looking for what it is REALLY classified as, but didn't have time to look it up.

BillC




"Nobel gas"?


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Brent]
      #5643057 - 01/25/13 05:52 PM

Bingo! Thanks!

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jon Isaacs
Postmaster
*****

Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Brent]
      #5643178 - 01/25/13 07:09 PM

Quote:

Quote:

I was looking for what it is REALLY classified as, but didn't have time to look it up.

BillC




"Nobel gas"?




Nobel gasses are the monatomic gasses, the gasses in the helium group.

Nitrogen is non-flammable, not an oxidizer but obviously, it does form chemical compounds under certain circumstances...


If your binoculars are fogging up internally, just fill them up with good quality distilled water.

jon


Post Extras: Print Post   Remind Me!   Notify Moderator  
faackanders2
Carpal Tunnel


Reged: 03/28/11

Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5643491 - 01/25/13 10:31 PM

Quote:

For the longivity of any binocular keeping it free of moisture is preferable to keeping it wet, irrespective of the claims and specs.
However in a situation were the wet is unavoidable say search and rescue, coast guard and naval use then its worth noteing that they buy the very best available for that particular enviroment,DA.




Some of us live where we get alot of dew or ice. I often stop observing when all my eyepieces are dewed or iced up.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rocket_pc
newbie


Reged: 01/24/13

Re: Nitrogen filled verses non-nitrogen binos new [Re: faackanders2]
      #5643528 - 01/25/13 10:56 PM

Pardon me for my tardiness in returning to this forum. I was up all night/mid-morning and got started late this evening from rest. At least my evening schedule is compatible with astronomy - when observing the sky, that is.

I am wondering about the point that the nitrogen is to prevent mold. It seems if the interior is clean from manufacture and sealed, mold spores couldn't get in. I guess that would be another reason to keep the scope sealed with a pure form of gas. I don't know chemistry but I think that nitrogen would be safer than oxygen or hydrogen. I remember somebody saying that the air is 70% nitrogen.

What I was asking about, is if the binoculars pressurized with nitrogen are safe from impact. I don't expect anything to survive a long distant drop to a concrete pavement. I wondering if these binos can take impact if in backpacks and luggage that is dropped on the floor a few feet or thrown into a car trunk by somebody unaware of the contents. I would never locate binoculars on the bottom of a bag, so there would be some insulation from impact. Then there is extreme temperatures, and other things I mentioned.

Somebody said that these binos are rugged and another mentioned that military uses them, though he says he regurly disposes of them. If these binos can survive military use, they can withstand heavy use.

So, deciding between the Nikon Extremes with 10x50 power and the Orion 15x70. In either case, I should take care of them: the Nikon because of its nitrogen seal and the Orions because probably more fragile in construction. I like Nikons - my first good camera was a Nikormat. But I think I would like the telescopic equivelence of the 15x70. (I think some description said the 15x70 is equivelent to a six inch diameter telescope. Is that correct?)


D.


Post Extras: Print Post   Remind Me!   Notify Moderator  
rocket_pc
newbie


Reged: 01/24/13

Re: Nitrogen filled verses non-nitrogen binos new [Re: rocket_pc]
      #5643536 - 01/25/13 11:00 PM

Oh yeah, an important factor in the comparison is if Orion 15x70 would have problems with fogging up.

D.


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: rocket_pc]
      #5643643 - 01/26/13 12:37 AM

“Pardon me for my tardiness in returning to this forum.”

Sorry, the vice-principal needs a note from a parent!

I think you are over-thinking this; buy quality and don’t worry. My Nikon SE is not rated at all as waterproof. But I doubt I ever have a problem.

“I am wondering about the point that the nitrogen is to prevent mold. It seems if the interior is clean from manufacture and sealed, mold spores couldn't get in.”

There’s clean and then there’s CLEAN. A man who uses a bino for his livelihood 800 miles out in the Gulf of Alaska needs — and paid for -- the latter.

“I guess that would be another reason to keep the scope sealed with a pure form of gas. I don't know chemistry but I think that nitrogen would be safer than oxygen or hydrogen. I remember somebody saying that the air is 70% nitrogen.”

78% but who’s counting?

“What I was asking about, is if the binoculars pressurized with nitrogen are safe from impact.”

There's VERY little pressure; it’s not there for that purpose. And no; you can rubber coat an egg, but it’s still an egg.

“I don't expect anything to survive a long distant drop to a concrete pavement. I wondering if these binos can take impact if in backpacks and luggage that is dropped on the floor a few feet or thrown into a car trunk by somebody unaware of the contents. I would never locate binoculars on the bottom of a bag, so there would be some insulation from impact. Then there is extreme temperatures, and other things I mentioned.”

Some of the cheap binos talked about on CN will decompose in your hands. Get a good, marine glass and you’re pretty darn safe.

“Somebody said that these binos are rugged and another mentioned that military uses them, though he says he regurly disposes of them. If these binos can survive military use, they can withstand heavy use.”

I think I’m gonna let you answer your own question on THAT one.

“So, deciding between the Nikon Extremes with 10x50 power and the Orion 15x70. In either case, I should take care of them: the Nikon because of its nitrogen seal and the Orions because probably more fragile in construction. I like Nikons - my first good camera was a Nikormat. But I think I would like the telescopic equivelence of the 15x70. (I think some description said the 15x70 is equivelent to a six inch diameter telescope. Is that correct?)”
10x50 power? How about 10 power by 50mm objective? NEITHER of these instruments is in the waterproof league as the serious military / marine glasses. As far as the equivalent to a 6-inch. NO!

One misconception concerning binoculars that never seems to go away is that its light grasp consists of the SUM from both objectives. This is possibly intuitive; but definitely wrong. The light grasp does consist of both sides, mathematically; but the human body does not work on mathematics. The brain accepts very little more than the light grasp from ONE objective! You may prove this to yourself.

Inside or out, find a well-lighted environment and place one hand over an eye. Do it a number of times, paying attention to what you notice.

If what many believe about combined light grasp (binocular summation) were true, everything in sight would suddenly become half as bright when your hand was over your eye. Did that happen? Humm!

There is, however, an advantage to using both eyes. While the brain accepts little more than the light grasp from one objective, using both eyes can allow us up to 40% more contrast. This is especially noticeable to amateur astronomers who routinely observe fields of brilliant stars against a black background.

In addition, there is an averaging factor which allows us more resolution by using both eyes. The ocean of atmosphere we live under consists of an almost infinite number of “heat cells.” According to science, these invisible cells are 4-6 inches in diameter and always in motion. We get the averaging effect in our seeing due to not being able to look through the same set of cells in our field of view at the same time—one set always being more stable than the other.

“D.”
BC


Post Extras: Print Post   Remind Me!   Notify Moderator  
rocket_pc
newbie


Reged: 01/24/13

Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5643754 - 01/26/13 03:18 AM

Interesting comments, especially about the cells of warm air.
Somebody commented that he would he would quit for the evening after his equipment fogged. If there were a cloud of fog over the area, I would. If a fog because of humidity and cold air, I wouldn't want to quit, considering the trouble of getting to a site, and getting a clear night (those can be rare in the midwest). The sky could be clear and still have moisture problem on the ground. Thus, I think that would be a good case for fog-resistent binos...


Post Extras: Print Post   Remind Me!   Notify Moderator  
Lane
Post Laureate


Reged: 11/19/07

Loc: Frisco, Texas
Re: Nitrogen filled verses non-nitrogen binos new [Re: rocket_pc]
      #5643781 - 01/26/13 04:04 AM

Quote:

Hi, I am newly subbed to Cloudy Nights. I already have a subject to ask about.

I am interested in purchasing a new pair of binoculars. I am trying to decide between a pair of binoculars that are nitrogen filled (fog resistent) (for example, the Nikon Action Extreme 10x50) and non-nitrogen filled binoculars (For example the Orion 15x70). The main concern I have about the nitrogen filled feature is that I wonder if the nitrogen can be discharged by impact (while in luggage that has been handled roughly for example) or gradually leak over time. I think of vacuum aluminum thermos bottles that never keep their pressure. I could get non-nitrogen binos with much higher magnification for almost half the price of nitrogen filled binos.

Thank you for your time on this subject.

D.




I have never had a pair of binoculars fog up on the inside or get water on the inside and my primary observing site is usually soaked in dew by midnight. I have a pair of 30 year old 10x50s have been used up there for years with no problems. My favorite binoculars are 9x63 Orion MiniGiants and I have had no problems with them either.

Waterproof/Fogproof usually means a half pound of extra weight too.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Binojunky
Carpal Tunnel
*****

Reged: 12/25/10

Re: Nitrogen filled verses non-nitrogen binos new [Re: Lane]
      #5644339 - 01/26/13 12:48 PM

Not really related but Nitrogen is used in the aircraft industry, when I was in the RAF we used it in the hydraulic accumulators as their was no chance of detonation, also used in aircraft tires,in this case it kept its pressure fairly stable even going from the extremes of a hot aircraft pan in the blazing sun to freezing altitudes of over 55,000 ft, in the event of a tire or brake fire the released gas would not support combustion.
If memory is correct the mainwheel tires on the English Electric Lightning were inflated to around 325-350 psi, sorry for going off topic,DA.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Scott in NCAdministrator
80mm Refractor Fanatic
*****

Reged: 03/05/05

Loc: NC
Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5644448 - 01/26/13 01:55 PM

Very interesting info, Dave--thanks for sharing that (and no, it wasn't really too far OT)!

Post Extras: Print Post   Remind Me!   Notify Moderator  
faackanders2
Carpal Tunnel


Reged: 03/28/11

Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5644556 - 01/26/13 02:56 PM

Quote:

Not really related but Nitrogen is used in the aircraft industry, when I was in the RAF we used it in the hydraulic accumulators as their was no chance of detonation, also used in aircraft tires,in this case it kept its pressure fairly stable even going from the extremes of a hot aircraft pan in the blazing sun to freezing altitudes of over 55,000 ft, in the event of a tire or brake fire the released gas would not support combustion.
If memory is correct the mainwheel tires on the English Electric Lightning were inflated to around 325-350 psi, sorry for going off topic,DA.




I assume nitrogen filled auto tires are to reduce internal oxidation or dry rot inside the tires, and make them last longer and not crack inside.


Post Extras: Print Post   Remind Me!   Notify Moderator  
faackanders2
Carpal Tunnel


Reged: 03/28/11

Re: Nitrogen filled verses non-nitrogen binos new [Re: rocket_pc]
      #5644578 - 01/26/13 03:09 PM

Quote:


Somebody said that these binos are rugged and another mentioned that military uses them, though he says he regurly disposes of them. If these binos can survive military use, they can withstand heavy use.
D.




Military definitely gets their stuff wet! Not just Navy Coastguard. Think Army soldiers outside in the rain, or crossing a swap, or creek.

I remember one general looking at a computer and asking the supplier will it work if dropped in the mud. Military computers hhave a rubber over on top of they keyboard w/o gaps for water to get in.

Getting back to amateur astronomy, we do observe with dew, and ice, sometimes we quit with fog but it does take a while to pack up. Sometimes we leave out equipment set up at star parties after we go to sleep. Sometimes the ice stays on our stuff in the car throught the night (at star parties when we camp). Yes, our stuff does get wet at times!


Post Extras: Print Post   Remind Me!   Notify Moderator  
faackanders2
Carpal Tunnel


Reged: 03/28/11

Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5644590 - 01/26/13 03:19 PM

When they say binos have twice the light grasp they mean each eye gets the full aperture of that one objective; whereas binoviewers split the objectives light in half for both eyes. You get more clarity with both eyes cancelling out noise and averaging, but the objects still have to be pulled out of the background (and does not sum up both eyes). If you can't see it in either eye, you won't see it combined w3ith both eyes (even if just barely below visibility).

Post Extras: Print Post   Remind Me!   Notify Moderator  
George9
sage


Reged: 12/11/04

Re: Nitrogen filled verses non-nitrogen binos new [Re: faackanders2]
      #5645077 - 01/26/13 08:26 PM

The Canon IS binoculars, which are listed as weather-proof (not sealed), can fog on the inside. Mine spend a month in 100% humidity every year, and with the evening drop in temperature, they fogged inside the objectives. The solution was simple: during that month, I keep them in a plastic bag with dessicant when they are stored. During any given observing session, not enough humidity gets in to cause a problem.

Of my several sealed binoculars, none have ever fogged under the same conditions, so I don't bother with the bag and dessicant.

Therefore, nitrogen filled or not, a well-sealed binocular is valuable.

George


Post Extras: Print Post   Remind Me!   Notify Moderator  
faackanders2
Carpal Tunnel


Reged: 03/28/11

Re: Nitrogen filled verses non-nitrogen binos new [Re: George9]
      #5646333 - 01/27/13 04:12 PM

A openen jar of flower drying pellets works well also.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Binojunky
Carpal Tunnel
*****

Reged: 12/25/10

Re: Nitrogen filled verses non-nitrogen binos new [Re: faackanders2]
      #5652085 - 01/30/13 11:24 AM

I believe car use is related to the low pressure sensors that a lot of manufactures are fitting, nitrogen will not expand and contract like normal compressed air in tempreture variations and it probably helps with condensation internaly,also its used in a lot of binos to prevent fogging as the O.P. mentioned,DA.

Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5652104 - 01/30/13 11:30 AM

Quote:

I believe car use is related to the low pressure sensors that a lot of manufactures are fitting, nitrogen will not expand and contract like normal compressed air in tempreture variations and it probably helps with condensation internaly,also its used in a lot of binos to prevent fogging as the O.P. mentioned,DA.




BS, PV=nRT you can look it up.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mark9473
Postmaster
*****

Reged: 07/21/05

Loc: 51°N 4°E
Re: Nitrogen filled verses non-nitrogen binos new [Re: bierbelly]
      #5652388 - 01/30/13 01:54 PM

Well, what is true is that nitrogen will contract and expand much less than moist air where condensation of the moisture is something not taken into account in the Ideal Gas Law you quoted.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Binojunky
Carpal Tunnel
*****

Reged: 12/25/10

Re: Nitrogen filled verses non-nitrogen binos new [Re: Mark9473]
      #5652527 - 01/30/13 03:15 PM

Excuse my uneducated question bierbelly but what exactly is the BS meaning in your reply?, if its Bull Manure then its not exactly a nice responce,however all gasses expand and contract to some degree, however nitrogen is a more stable medium,DA.

Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5652575 - 01/30/13 03:41 PM

Methane molecules are huge! Every time I fill a room with methene, it tends to linger.

Post Extras: Print Post   Remind Me!   Notify Moderator  
hallelujah
Post Laureate
*****

Reged: 07/14/06

Loc: North Star over Colorado
Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5652617 - 01/30/13 03:57 PM

http://www.birdforum.net/showthread.php?t=52292

Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5652636 - 01/30/13 04:05 PM

Quote:

Excuse my uneducated question bierbelly but what exactly is the BS meaning in your reply?, if its Bull Manure then its not exactly a nice responce,however all gasses expand and contract to some degree, however nitrogen is a more stable medium,DA.




Sorry, nothing personal intended. Just tired of hearing how special nitrogen is as compared to air. The Ideal Gas Law, which is applicable under all circumstances to all gases (with the exception to those under extreme pressures, like CO2, which liquifies) dictates that all gases expand the same amount under identical temperature and pressure conditions. N2, Ar, Air, Xe, Kr, He, even Cl2.

People are letting themselves be manipulated by marketing. Further, because of diffusion of gases through membranes, the nitrogen you put in your tires isn't going to be pure nitrogen for very long, especially if your tires get hot (which of course they do), since gases will diffuse even more quickly through a hot membrane (tire bead).


Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Mark9473]
      #5652649 - 01/30/13 04:10 PM

Quote:

Well, what is true is that nitrogen will contract and expand much less than moist air where condensation of the moisture is something not taken into account in the Ideal Gas Law you quoted.




No, think of the air and the moisture as being two different gases, which they are. The air and the nitrogen will expand/contract exactly the same. In fact, if the moisture is in gaseous form, it will too. The difference is if you have liquid water at one temperature and then gaseous water at a second temperature...ie different phases of the component.

Realistically, anyone who's using air to fill things like binocs ought to be using air from a system with a moisture knockout, at the very least.


Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5652653 - 01/30/13 04:11 PM

Quote:

Methane molecules are huge! Every time I fill a room with methene, it tends to linger.




This is absolutely true and the one exception to the Ideal Gas Law...of course, methane is NOT ideal...


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: bierbelly]
      #5652655 - 01/30/13 04:13 PM

"Sorry, nothing personal intended. Just tired of hearing how special nitrogen is as compared to air." "People are letting themselves be manipulated by marketing."

Boy, Bierbelly, keep it up and maybe you could pull some of the heat off me! Bat and Wyatt could ride, again.

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mark9473
Postmaster
*****

Reged: 07/21/05

Loc: 51°N 4°E
Re: Nitrogen filled verses non-nitrogen binos new [Re: bierbelly]
      #5652659 - 01/30/13 04:14 PM

Quote:

The difference is if you have liquid water at one temperature and then gaseous water at a second temperature.



That was exactly my point.


Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Mark9473]
      #5652666 - 01/30/13 04:16 PM

Quote:

Quote:

The difference is if you have liquid water at one temperature and then gaseous water at a second temperature.



That was exactly my point.




Yes, if you have very moist air inside your binocs, and you take them out to a cold climate, once the glass gets down to ambient, they're gonna fog on the inside. The best solution would be to carry a large nitrogen tank with you, install inlet connections on each barrel and continuously purge the binocs with N2 during your observing session.


Post Extras: Print Post   Remind Me!   Notify Moderator  
FrankL
sage


Reged: 07/30/09

Loc: Winnipeg, Manitoba Canada
Re: Nitrogen filled verses non-nitrogen binos new [Re: bierbelly]
      #5652799 - 01/30/13 05:12 PM

If I'm understanding correctly manufacturers purge binoculars with nitrogen to ensure that upon leaving the factory they are perfectly dry inside so that no fungus or condensation effects can occur. However, eventually no matter how well the binocular is sealed the nitrogen will permeate through the sealings and be lost. My question is about how long would this take in a well sealed binocular made by a top-end maker such as Leica, Zeiss, Swarovski, Nikon?

Edited by FrankL (01/30/13 05:14 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mark9473
Postmaster
*****

Reged: 07/21/05

Loc: 51°N 4°E
Re: Nitrogen filled verses non-nitrogen binos new [Re: FrankL]
      #5652844 - 01/30/13 05:39 PM

The nitrogen isn't lost, the issue is that moisture gets in.

Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: FrankL]
      #5652917 - 01/30/13 06:14 PM

Hi Frank:

Buy a good bino and don't worry about it!

It has been quite some time since I waved the flag that says “CN is full of complex and laborious solutions to non-existent problems.” It’s time, again.

The skinny:

If you spend the money for a binocular designed for the real working man or woman, like the MT, FMT, MTR, FMTR, AR or Mariner from Fujinon, find an old Seahawk or Storm King from Swift or their equal you’ll PROBABLY NEVER have to worry about it.

If you get sucked into one of the many bargain basement binos touted as water-proof, you should keep them in a zip-lock bag with a silica pouch.

You mention some pretty powerful names. Yet, it would be got to recognize “all that glitters is not gold.”

At the expense of causing an echo, during my last 10 years at Captain’s, most of the marine binos went back out un-purged, at the customer’s request. NOT ONE ever came back with moisture related problems!

A bino is sealed or it isn’t. And by “sealed” I mean over the long haul. Some cheap “Waterproof” binos sold today, and are waterproof today, may not be after 6 months in the elements.

Just a thought.

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tony Flanders
Postmaster
*****

Reged: 05/18/06

Loc: Cambridge, MA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: bierbelly]
      #5652971 - 01/30/13 06:33 PM

Quote:

methane is NOT ideal...




Technically, it is an ignoble gas. And ignitable, too, but that's a whole 'nother subject ...


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Tony Flanders]
      #5653011 - 01/30/13 06:53 PM

"And ignitable, too,"

And, you would know . . . how?


Post Extras: Print Post   Remind Me!   Notify Moderator  
ErixAdministrator
Toad Lily
*****

Reged: 12/25/04

Loc: Texas, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5653018 - 01/30/13 06:56 PM

Binoculars and nitrogen, guys.

Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: FrankL]
      #5653019 - 01/30/13 06:57 PM

Quote:

If I'm understanding correctly manufacturers purge binoculars with nitrogen to ensure that upon leaving the factory they are perfectly dry inside so that no fungus or condensation effects can occur. However, eventually no matter how well the binocular is sealed the nitrogen will permeate through the sealings and be lost. My question is about how long would this take in a well sealed binocular made by a top-end maker such as Leica, Zeiss, Swarovski, Nikon?




Well, a well-sealed pair probably won't let that much moisture in, unless you leave them underwater. I have no idea how "waterproof" the binos sold as such are. In either event, if they are well sealed, there likely won't be enough moisture getting in to fog the objectives.

My point is not to be fooled by the marketing ploy of "nitrogen filled". IMHO, it means nothing. Don't pay extra for that.


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: bierbelly]
      #5653087 - 01/30/13 07:42 PM

"Binoculars and nitrogen, guys."

Yes, mam.

BC


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5653101 - 01/30/13 07:46 PM

Several years ago "Practical Sailor" ran an article in which a commercial fisherman reported finding a Swift Storm King that had been under 5-feet of water for over a year. It had crustaceans all over it but not a drop inside. He cleaned it off and it became his NEW best binocular.

I'm reporting this because experience teaches me to believe it.

BillC

Edited by BillC (01/31/13 12:05 AM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Binojunky
Carpal Tunnel
*****

Reged: 12/25/10

Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5654096 - 01/31/13 11:05 AM

No problem Bierbelly ,I got the same marketing guff when I got my truck, even has the green valve caps on the tires to "remind me in my senile years" to top up with nitrogen, however most filling stations are not equiped with it and just have regular compressed air which they are charging for, in Canada anyway. Not likeing to pay for a item that once was free I use a 12V air compressor at home and have had no problems.To get back to the original topic, some binoculars are advertised as filled with Argon, whats the advantage of that over Nitrogen or regular air for that matter?, thanks,DA

Post Extras: Print Post   Remind Me!   Notify Moderator  
rydberg
scholastic sledgehammer
*****

Reged: 02/25/04

Loc: Richmond, KY, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Binojunky]
      #5654111 - 01/31/13 11:16 AM

Argon is an inert gas heavier than Nitrogen (and therefore air). The rationale (I think) is that if you fill them with Argon, air cannot penetrate the binoculars (because Argon is heavier), any water and oxygen is dislodged out and no corrosion or fogging can take place. It works, but only if the seals are good. So we are back to the same story as nitrogen.
Marco


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: rydberg]
      #5654145 - 01/31/13 11:28 AM

'Sure glad it's not this complicated in the real world.

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
bierbelly
Postmaster
*****

Reged: 01/23/04

Loc: Sterling, VA
Re: Nitrogen filled verses non-nitrogen binos new [Re: rydberg]
      #5654209 - 01/31/13 12:04 PM

Quote:

Argon is an inert gas heavier than Nitrogen (and therefore air). The rationale (I think) is that if you fill them with Argon, air cannot penetrate the binoculars (because Argon is heavier), any water and oxygen is dislodged out and no corrosion or fogging can take place. It works, but only if the seals are good. So we are back to the same story as nitrogen.
Marco




Short story. When employed as a laboratory chemist for Airco (later BOC) Specialty Gases, we were terribly concerned with obtaining the driest gas possible as a "zero" gas for our moisture analyzer. In an effort to clean up even our own, extremely dry nitrogen zero gas, which evolved from a liquid nitrogen receiver on-site, we inserted a commercially available gas drier upstream of the analyzer, which was marketed for use in removing moisture from gas chromatography supply gases in laboratories.

After a reasonable length of time, to permit the lines to purge and the moisture analyzer to settle down (about 2 days of purging), we noticed that the moisture content of the "zero" gas had actually risen considerably! We concluded that the gas drier, which contained Drierite pellets and was constructed of polycarbonate, with some type of rubber o-rings sealing threaded metal end caps, was actually contributing more moisture to the system than the gas had "undried"!

We concluded that moisture was entering through either or both of the polycarbonate cylinder walls or the rubber o-rings (which even at that time were some more exotic polymer, not just plain rubber).

Remember, this was a system which was being continually purged with extremely dry nitrogen, not a static system like that which would exist in a tire, or a bino, so moisture couldn't continue to accumulate.

In my experience, the ONLY seals which can absolutely prevent the permeation of moisture (or really any unwanted contaminant gas present outside the system) is a metal-to-metal seal...and even that has to be quite robustly compressed or even soldered/welded to do the trick. That may be how waterproof binoculars are constructed, with a metal band around the lenses which is silver soldered to the races holding them into the barrels. How they seal the glass to the metal bands is beyond me.


Post Extras: Print Post   Remind Me!   Notify Moderator  
ronharper
Carpal Tunnel
*****

Reged: 02/14/06

Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5654234 - 01/31/13 12:24 PM

If you buy the Argon argument, your ultimate binocular bragging gas might be sulfur hexafluoride, atomic mass 146! As vile as it sounds it is inert, and the molecule is so big it would diffuse like cold molasses. There may be even more massive halides, I don't know.

It is way heavier than air, and a much better electrical insulator too. I recently filled a fish tank with it and operated a problematic high voltage device on the bottom--cured the sparking! I also floated aluminum foil boats and such on the invisible surface--just nutty. But it's a greenhouse gas, and wouldn't get along well with "eco" glass.

Ron


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: ronharper]
      #5654349 - 01/31/13 01:38 PM

The metamorphasis of threads.

This one started out ill-informed and has passed through silly, rediculous and inane. But now, it has emerged into the informative and potentially useful.

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
Mark9473
Postmaster
*****

Reged: 07/21/05

Loc: 51°N 4°E
Re: Nitrogen filled verses non-nitrogen binos new [Re: rydberg]
      #5654512 - 01/31/13 03:18 PM

Quote:

Argon is an inert gas heavier than Nitrogen (and therefore air). The rationale (I think) is that if you fill them with Argon, air cannot penetrate the binoculars (because Argon is heavier), any water and oxygen is dislodged out and no corrosion or fogging can take place.



That's not true. The driving force for oxygen and water vapour to enter the binoculars is the difference in partial pressure of those two gases inside and outside. That difference is identical regardless of which other gas is inside the binocular.

The only thing the argon does is to make a statement that this company has given some thought to sealing the binoculars and that if they're a reputable company you're lead to believe they've invested in better seals. There is no technical advantage to argon.


Post Extras: Print Post   Remind Me!   Notify Moderator  
KennyJ
The British Flash
*****

Reged: 04/27/03

Loc: Lancashire UK
Re: Nitrogen filled verses non-nitrogen binos new [Re: Mark9473]
      #5654593 - 01/31/13 03:59 PM

The way I have the site forums displayed, the title of this thread appears as "Nitrogen filled verses".

I thought it was just a thread about relatively safe poetry!

I've used bottled nitrogen regularly over the past 30 years or so for purging through industrial natural gas pipe installations to render the pipework safe for welding work and after decommissioning large installations such as in factories and warehouses when the premises are to become vacant for indefinite periods.

The first and last things that must be done before and after carrying out these types of works is to test the installations for gas tightness to prove no leakage.

For the sake of this post, to simplify the procedure to ignore situations where sections of pipework may pass,for example,both underground and outside,exposed to sunlight,when variations in temperature need to be taken into account, there are strict industry standard procedures and formulae for calculating duration of the tests, an important factor which varies proportionately to the volume of pipework involved, and the systems are left pressurised with nitrogen at whatever the test pressure happened to have been.

On several occasions I have returned to such a site after a number of months or even years, to recommission for incoming new tenants, eventually replacing the nitrogen with 100% natural gas, to find the pressure in the system the same as it was when left, indicating no discernible leakage whatsoever.

In cases of all-welded joints,this is a good example of "metal to metal seals" holding good,although in the case of screwed/threaded joints, not a single one would ever hold tight under such testing if it wasn't for the presence of gas jointing compound.

I can also think of many examples where plastic joints and fittings have held tight for many years under much higher mains water pressure.

I'm not sure what it is about WELL MADE binoculars that makes us users so paranoid about moisture ingress.

Kenny


Post Extras: Print Post   Remind Me!   Notify Moderator  
ronharper
Carpal Tunnel
*****

Reged: 02/14/06

Re: Nitrogen filled verses non-nitrogen binos new [Re: Mark9473]
      #5654596 - 01/31/13 04:01 PM

Mark,
You are correct, that diffusion will continue until the inside and outside partial pressures are equal. But, in principle at least, I think there would be a difference for different gases: the diffusion will proceed more slowly, the more massive and bigger the molecule. At a given temperature, velocity varies as the inverse of the square root of the mass, so even SF6 would still be going about half as fast as N2, hardly a big effect. For Ar vs N2, the velocity difference is only 20%. The quality of the sealing would probably play a much bigger role in the duration of gas containment, than the mass of the molecules.

Pardon my, uh, hot air.
Ron

Kenny,
I think it's just that there's no common test to verify that a binocular actually has N2 in it that causes such merriment and discussion. But after reading Bill's real world accounts of the performance of good marine binoculars in bad conditions, my mind has been set much more at ease about this. How was I supposed to know, unless somebody told me? BillC does it a again.
Ron


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: ronharper]
      #5654666 - 01/31/13 04:46 PM

Yep, veritable legend in his own . . . MIND. 'Anybody lend me a buck for a Coke?

Cheers,

BillC

PS ALSO, please remember there are many instruments out there touted as "good marine binoculars," when, in fact, it's all a sham, like all those plastic-based ZOOM binoculars that are sold as "Military."

"Buyer Beware" does not BEGIN to cover the need. How is a person to know? Find a friend who does, and is willing to put his reputation behind his words. That's where the rubber meets the road.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jarrod
Pooh-Bah
*****

Reged: 01/20/13

Loc: SE USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: rydberg]
      #5654671 - 01/31/13 04:49 PM

Chemist here. I retired from the lab years ago and do theoretical work now ;-)

I believe that the reason for nitrogen has everything to do with taking advantage of differential gas densities to completely purge the desiccators that are used during manufacturing. N2 has a higher density than H2O vapor. So when they purge the desiccators, they introduce pressurized, dry nitrogen (very cheap and easy to produce) at the bottom and force gas out the top, where any lingering H2O vapor would be hanging out. This has everything to do with keeping the manufacturing environment dry and nothing about the end-product having nitrogen-filled tubes. They could use any gas that is heavier than H2O vapor, but N2 is the most abundant and therefore cheapest.

A similar technique is used when running reactions that involve pyrophoric chemicals (chemicals that spontaneously combust when the contact water). You flow the inert gas in from the bottom, to get maximum evacuation of the water vapor from the reaction vessel. Trust me, it's important. I have scars to prove it. Thankfully, they are only mental scars - I was wearing gloves and a lab coat.

Edit: I appear to have the direction wrong. These devices are more complex than our little chemistry setup was. http://www.terrauniversal.com/desiccators-dry-boxes/nitrogen-purge-desiccator...

Edited by Jarrod (01/31/13 05:11 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
KennyJ
The British Flash
*****

Reged: 04/27/03

Loc: Lancashire UK
Re: Nitrogen filled verses non-nitrogen binos new [Re: Jarrod]
      #5654755 - 01/31/13 05:37 PM

In my capacity as a British Gas Industrial and Commercial Technician/acting supervisor back in 1986,I recall attending a meeting amongst various"specialists" and "superiors" that became quite heated.

The debate surrounded the question" What is the optimum PRESSURE at which nitrogen ought to be introduced to purge out a large installation containing natural gas in order to ensure or maximise as far as practically possible the COMPLETE displacement of the combustible gas".

The two main opposing schools of thoughts were thus:

1. It is possible,if TOO HIGH a pressure/velocity is applied, for the nitrogen to "force" the natural gas to the outer perimeters of the inside of the pipe, making it possible to leave significant traces of the potentially combustible gas remaining in spite of methane sensing instruments ( called Gascoseekers) placed at the outlets reading less than 1% GAS ( or 20% Lower Explosive Limit - limits being between 5% and 15% in AIR ).

2. The HIGHER the purging pressure/ nitrogen velocity, the more thorough the purging operation will be.

The latter was proven to be correct.

Kenny


Post Extras: Print Post   Remind Me!   Notify Moderator  
Jarrod
Pooh-Bah
*****

Reged: 01/20/13

Loc: SE USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: KennyJ]
      #5654767 - 01/31/13 05:46 PM

Big respect for that, Kenny. I have a good fraction of my savings invested in North American NG pipes. It's a great industry. I used to have BP as well, before the accident....

Very interesting to read your comments on purging pipe. I imagine those considerations are big-time important before you contemplate putting an acetylene torch to a pipe that had pressurized, flammable substances flowing through it!

Edited by Jarrod (01/31/13 05:50 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
KennyJ
The British Flash
*****

Reged: 04/27/03

Loc: Lancashire UK
Re: Nitrogen filled verses non-nitrogen binos new [Re: Jarrod]
      #5654896 - 01/31/13 07:01 PM

Thank you,Jarrod.

As you implied,it's ONE thing sitting around well crafted tables in plush surroundings,wearing expensive suits,drinking fine coffee from the best china cups,TALKING about a potential problem,but it can be somewhat different out on the front line,freezing private parts off or sweating like a pig,heart beating like a drum,whilst actually putting the theories into practice,knowing that any mistake can literally spell the end of existence for more than just yourself.

Of course,repairing binoculars is not quite such a potential "life and death" profession,but again,there are far fewer people who actually carry out the work professionally than there are who seem to enjoy speculating about it!

Kenny


Post Extras: Print Post   Remind Me!   Notify Moderator  
BillC
on a new path
*****

Reged: 06/04/04

Loc: Lake Stevens, WA, USA
Re: Nitrogen filled verses non-nitrogen binos new [Re: KennyJ]
      #5654916 - 01/31/13 07:13 PM

Everybody put your hands on the computer screen and say Amen!

BillC


Post Extras: Print Post   Remind Me!   Notify Moderator  
RichD
Carpal Tunnel


Reged: 11/08/07

Loc: Derbyshire, UK
Re: Nitrogen filled verses non-nitrogen binos new [Re: BillC]
      #5655620 - 02/01/13 06:11 AM

very interesting Kenny

Post Extras: Print Post   Remind Me!   Notify Moderator  
Jon Isaacs
Postmaster
*****

Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Nitrogen filled verses non-nitrogen binos new [Re: Jarrod]
      #5655894 - 02/01/13 09:25 AM

A few thoughts:

- Bicycle inner tubes are an example of the diffusion of air through butyl rubber. A standard 700C-23 tire pumped to 120psi will lose enough pressure that it will need to be pumped up within a week or so. Bicycle tires are operating at high pressures, with large surface areas, are quite thin and the enclosed volume is relatively small.

- Binoculars are quite a different situation. There is very little pressure differential driving the diffusion, there may be none. I suspect Jarrod is correct, the reason for the purging is to dry the internals of the binoculars, the purpose of the O-Rings is the prevent moisture from entering the binoculars.

In my line of work, when I want something to be really dry, I hook it up to a vacuum pump and pull it down to micron levels...

Jon


Post Extras: Print Post   Remind Me!   Notify Moderator  
Binojunky
Carpal Tunnel
*****

Reged: 12/25/10

Re: Nitrogen filled verses non-nitrogen binos new [Re: Jon Isaacs]
      #5656378 - 02/01/13 01:33 PM

Talking about sealing stuff, a few years back I pulled apart a VW air cooled motor and the cylinder head mated to the cylinder barrels with no gasket of any sort, not sure of the PSI when the piston was a TDC but it worked.DA.

Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | 3 | 4 | (show all)


Extra information
9 registered and 29 anonymous users are browsing this forum.

Moderator:  Knuklhdastrnmr, WOBentley 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 3827

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics