Re: [Paddlewise] Waterproof Binoculars

Hi Dave,

Thanks for the patient and thorough correction. I always welcome the
opportunity to learn more.

I relied upon salespeople and consumer magazines for my "unscientific"
understanding. I should know better. Then again, it's always possible I
simply misunderstood.

You have me scratching my head about the use of nitrogen in racing tires. It
was my understanding that nitrogen maintained stable tire pressures. Tire
pressure is critical in affecting the car's handling. Yet, you suggest that
nitrogen cannot affect this meaningfully. Hmmm...

Racing tires have a VERY short lifespan. By the end of the day they're done.
So, I doubt, as you say, that nitrogen is employed for any reasons of
extending tire life.

Interesting as we may find this, others may be wondering why we're talking
about nitrogen in tires, and just what DOES this have to do with sea
kayaking anyway...  They're not INTERESTED in putting racing tires on their
kayaks, nitrogen-filled or otherwise. ; )

Your Nikon TravelLites are a perfect example of Nikon value at any given
consumer price point. They are generally regarded as having the best optics
available in that price range. But, dealers have told me, just don't get
them wet. Water leaks into the interior through the central joint, not so
much around the lens elements, I've been told. They're not waterproof, of
course, and haven't been advertised as such. Great binoculars for the money.

Regards,

-Bruce

>
>A couple of small corrections to an otherwise excellent treatise on
>binocs:
>
>1. Nitrogen can hold water vapor, and in the same concentration as any
>other gas.  Air has no special property which allows it to hold more
>water vapor.  I think the binocs manufacturers purge (then fill) binocs
>with DRY nitrogen, which has had all moisture removed from it.  Then, as
>long as the O-ring seal is not compromised, no moisture can enter the
>binocs, and, voila!, no condensation on the inside.  Nitrogen is used as
>the purge gas (most likely) because dry nitrogen is useful commercially
>and is more available than dry air.
>
>2. It's not true that nitrogen will not expand when heated (re: comment
>about Indy sports cars).  The Ideal Gas Law applies equally to all gases
>(and, mixtures of gases) at the sorts of pressures and temperatures in
>tires.  I am puzzled, nonetheless, why they would bother to inflate with
>nitrogen, unless they are concerned about oxygen-stimulated degradation
>of the tire rubber.  That seems unlikely, given the short lifetime of
>Indy rubber.
>
>Thanks for an otherwise informative and authoritative treatise on
>binocs.  (I just invested in a waterproof pair of Canon binocs, after
>many years of avoiding a dunking for my Nikon TravelLites.)
>
>-- 
>Dave Kruger
>Astoria, OR
>sea kayaker -- and chemist

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