Tape Sag [Was: Re: fixed points in survex]

[Matt Ryan]

Perhaps I'm missing something here on tape sag, but aren't most tapes, at
least those intended for horizontal use, supposed to be calibrated at a
known tension - rather than at zero tension as you guys seem to be
suggesting.  The theory I thought being that you pull the tape to the
calibrated tension and read it at that.  Obviously using anything other
than a brand new clean tape is going to have a huge effect, as are
anything other than horizontal legs.  And then there's also the fact that
at very best people just guess the correct tension.

A nice piece of work Lev - now I've had chance to read it properly.

200 GBP for a Disto-lite laser rangefinder apparently.  Tempting...

-Matt

--=20
Matthew Ryan
matt@mdryan.net    <-- Please note my new e-mail address
www.mdryan.net