NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Artificial Horizon Levels
From: Robert Eno
Date: 2004 Mar 28, 13:30 -0500
From: Robert Eno
Date: 2004 Mar 28, 13:30 -0500
Hello List,
A question to ponder.
I have a Freiberger flat glass artificial
horizon that came with two longitudinal levels which are senistive to about
30 seconds of arc. They came already calibrated but do have a provision for
adjustment.
I've had this item for about 10 years and have
never dared tamper with the adjustment screws on the levels, however, it would
be useful to know how to calibrate them. My initial thought is that in order to
calibrate them, one must have a surface that one knows for a fact, is perfectly
level, however, this is unrealistic for the average
person.
I have stewed over this problem and decided that
logically, the way to calibrate the levels would be to find a spot that is
reasonably level, then place the level on that spot and note where the bubble
lies within the graduated lines on the level. Then one would turn the level 180
degrees on it's longitudinal axis and again note the position of the bubble. The
bubble should be within the same spot; if not, then one would have to adjust the
screw until the bubble moves halfway to its desired position. Then one
would again turn the level 180 degrees and do it all over again and keep going
back and forth until the bubble rests in the same spot.
Am I on the right track here? For that
matter, am I making any sense?
cheers,
Robert
