NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Getting ready for a spring demo...
From: Greg B
Date: 2013 Dec 30, 18:49 -0500
From: Greg B
Date: 2013 Dec 30, 18:49 -0500
OK I went to the Empire web site.
Trying to do it according to Frank and Mike:
First the Empire Level information from their website:
Levels with Empire True Blue® vials provide a maximum accuracy
- guaranteed accurate to .0005in. per inch
That's accuracy equal to the thickness of a dime over 8 feet
OK, according to the US Mint the thickness of a dime is 1.35mm
and I calculate that 8ft. = 2438.4 mm
so...
arcmin = 3438 X (1.35/2438.4) = 1.9'
If I did the math correct I still need something slightly better.
~Greg
On 12/30/2013 05:52 PM, Alan S wrote:
First the Empire Level information from their website:
Levels with Empire True Blue® vials provide a maximum accuracy
- guaranteed accurate to .0005in. per inch
That's accuracy equal to the thickness of a dime over 8 feet
OK, according to the US Mint the thickness of a dime is 1.35mm
and I calculate that 8ft. = 2438.4 mm
so...
arcmin = 3438 X (1.35/2438.4) = 1.9'
If I did the math correct I still need something slightly better.
~Greg
On 12/30/2013 05:52 PM, Alan S wrote:
Greg:
Re an accurate and inexpensive level, take a look at Empire Levels, in particular their 9" long torpedo level.. They claim accuracy of.0005"/". If I remember the numbers correctly that translates to around 20 seconds of arc.
Alan
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