watches unpressurized

A question to the group. When I was going through my high-altitude
physiological training, they instructed us to remove wrist watches
before going for the baro-flight to FL250 (unpressurized). Has
anyone experienced any anomalies with wrist watches at low pressure?
I just can't think of why they'd require that. Even diver's watches
will hold the pressure up to a point and then the seals will leak
-- before any damage to the body of the watch or the crystal occurs.
Does the battery have any air inside that will blow it up?


Andrey

"Andrey Serbinenko" wrote in message
...
A question to the group. When I was going through my high-altitude
physiological training, they instructed us to remove wrist watches
before going for the baro-flight to FL250 (unpressurized). Has
anyone experienced any anomalies with wrist watches at low pressure?
I just can't think of why they'd require that. Even diver's watches
will hold the pressure up to a point and then the seals will leak
-- before any damage to the body of the watch or the crystal occurs.
Does the battery have any air inside that will blow it up?


Andrey



Dive watches are designed to keep water out not to keep air in. That said,
probably 999 out of 1000 wouldn't have a problem but since one probably
popped on them once they just made up a new rule. You know how much
organizations like rules.

Andrey Serbinenko wrote:
A question to the group. When I was going through my high-altitude
physiological training, they instructed us to remove wrist watches
before going for the baro-flight to FL250 (unpressurized). Has
anyone experienced any anomalies with wrist watches at low pressure?
I just can't think of why they'd require that. Even diver's watches
will hold the pressure up to a point and then the seals will leak
-- before any damage to the body of the watch or the crystal occurs.
Does the battery have any air inside that will blow it up?


Andrey

I bought a cheap divers watch from a "large discount chain" to wear on
a trip to Equador. It did fine until we got to Quito. The altitude
there is 10,000 ft. After about 2 hours on the ground (during lunch,
in fact) the crystal popped out of the watch, flew across the table and
went rolling across the floor. I got it back and stuck it into the
watch face. It did fine after that. As noted, divers watches are
constructed to keep things from leaking in, not the other way around.
My guess is a good one wouldn't matter, but I wouldn't take the chance
unless I really needed a watch.

John Stevens
PP-ASEL

Gig 601XL Builder schrieb:

Dive watches are designed to keep water out not to keep air in.

Professional dive watches have an air valve.

"Stefan" wrote in message
...
Gig 601XL Builder schrieb:

Dive watches are designed to keep water out not to keep air in.

Professional dive watches have an air valve.

Add the word SOME or maybe even MOST and I'll agree. But it doesn't change
the keep air in statement I made. As a matter of fact it means they are
specifically made to let air out.

Gig 601XL Builder schrieb:

As a matter of fact it means they are
specifically made to let air out.

Of course, this was my point.

Andrey Serbinenko wrote:
A question to the group. When I was going through my high-altitude
physiological training, they instructed us to remove wrist watches
before going for the baro-flight to FL250 (unpressurized). Has
anyone experienced any anomalies with wrist watches at low pressure?
I just can't think of why they'd require that. Even diver's watches
will hold the pressure up to a point and then the seals will leak
-- before any damage to the body of the watch or the crystal occurs.
Does the battery have any air inside that will blow it up?


Andrey

I have had the crystal on my digital watch pop out while flying my
glider up to about 18,000 feet. True the watch was a few years old and
I just replaced it with the same kind.

Brian C.
CFIIG/ASEL

Gig 601XL Builder wrote:
As a matter of fact it means they are
specifically made to let air out.




Well, specifically, they are made to let helium out.

Watches off, has been standard for as long as I can remember.

If you did open the helium valve on the watch, I am not so sure it would
keep up with the rapid decompression portion of the profile, assuming
you had that. It is very very very small.

Come to think of it, I have had a watch (not a cheap one) to FL230, and
there were no problems. But it wasn't a rapid decompression. In fact
I'll bet there are lots of guys up over 20,000, zooming around breathing
oxygen.

I suppose if one wanted, you could unscrew the stem on you dive watch
and it could breath, but I wouldn't bother.

John





Brian wrote:

Andrey Serbinenko wrote:

A question to the group. When I was going through my high-altitude
physiological training, they instructed us to remove wrist watches
before going for the baro-flight to FL250 (unpressurized). Has
anyone experienced any anomalies with wrist watches at low pressure?
I just can't think of why they'd require that. Even diver's watches
will hold the pressure up to a point and then the seals will leak
-- before any damage to the body of the watch or the crystal occurs.
Does the battery have any air inside that will blow it up?


Andrey


I have had the crystal on my digital watch pop out while flying my
glider up to about 18,000 feet. True the watch was a few years old and
I just replaced it with the same kind.

Brian C.
CFIIG/ASEL

Gig 601XL Builder writes:

Add the word SOME or maybe even MOST and I'll agree. But it doesn't change
the keep air in statement I made. As a matter of fact it means they are
specifically made to let air out.

That's what you'd want them to do at FL250.

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