 Check out the bookstore at IRBS.com |
|
|
|
|||||
|
||||||
Subject: Re: Instrument repair
From: Paul Hirose (paulhirose@XXX.XXX)
Date: Wed Dec 18 2002 - 23:32:17 EST
Ken Gebhart wrote:
>
> lower lenses of the chamber. This is predicated on the fluid in the chamber being
> xylene, which it is in all aircraft sextants except the Kollsman periscopic
> sextant which has a silicone fluid, as does the C. Plath marine bubble chambers.
> We have not heard of a recommended size for these.
Thanks for a highly informative message; I archived it on my computer.
A copy of the Kollsman manual came with my sextant. It says,
"Suggested size of bubble is about 1 1/2 to 2 degrees (the sun appears
to subtend about one degree)."
At first I thought the manual was wrong about the sun's size, but then
I realized it must be including the sextant's 2x magnification.
I don't know why the writer didn't simply say to make the bubble about
1.5 to 2 times the diameter of the sun or full moon.
|