units for calibrate tape

Olly Betts olly at survex.com
Tue Aug 31 10:49:07 BST 2004

On Mon, Aug 30, 2004 at 11:08:04AM -0400, Philip Balister wrote:
> Last weekend I used a tape that was missing the first foot. I am trying
> to use the calibrate command to fix this. Do the units of calibrate
> follow the tape units (in my case feet) or are they always meters?

They're the tape units (i.e. the current setting of "*units tape" when the
*calibrate command is processed).  Looking at the manual, that's not
clear.  I'll fix that - thanks for pointing it out.

A good way to remember how *calibrate works (especially for getting the sign
correct) is to remember you specify the "zero error" - i.e. the reading the
instrument gives when it should read zero.  So if a tape is read in feet
and is a foot too short, then when the tape should read zero it actually
reads "1".

Incidentally, do you read in feet with a decimal fraction?  Or are you
reading feet + inches and converting externally?  It would be easy
enough to add support for feet + inches if it would be useful.


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