Topband: Laser distance meters

[Mike Waters]

Roy, this was *very* interesting! Thanks for sharing. :-)

73 Mike
W0BTU

On Sun, Jun 6, 2021, 3:04 PM Roy Morgan <k1lky68 at gmail.com> wrote:

> Topbanders interested in laser measurements,
>
> Here are some short stories.  During the time I worked at NIST (formerly
> NBS), I heard about these situation:
>
> The David Taylor Model Basin (since renamed) has a water-filled tank about
> 5/8 mile long for towing of scale models of ships to measure their
> performance. A team from the mechanical metrology group at NBS measured the
> flatness of the rails that carried the instrumented platform along the
> tank.  Their laser measurement systems found the middle of the tank to be
> about 5/8 inch above the expected straight line end to end.  It was the
> curvature of the earth causing the “bulge”.
>
> At a presentation to aircraft manufacturers about measurement systems
> being developed to more accurately make the major components of commercial
> aircraft, many of which were being made at different locations, the speaker
> noted that the Boeing 747 was assembled with shims to compensate for
> differences between major parts that had to fit together (wings, fuselage
> sections). “The 747 has a ton of shims”, he’d said.  “Wait a minute”, one
> Boeing engineer said, “How much do all those shims weigh?”  About a ton,
> was the reply - nearly two thousand pounds.  And that weight gets carried
> by the aircraft throughout its life.
>
> The NIST metrology building houses a highly accurately located GPS
> receiver to develop error information that is broadcast by radio (and
> presumably internet) useful for land surveyors to correct their laser
> surveying instrument results.  (One of the US’s primary geolocation points
> is on the NIST grounds and forms the basis for all surveying done in the
> Eastern part of the continent.)
>
>
> > On Jun 6, 2021, at 12:58 AM, Richard (Rick) Karlquist <
> richard at karlquist.com> wrote:
> >
> > I am considering replacing my 100 meter tape measures with
> > a Bosch GLM400CL laser distance meter to use for laying out
> > my next 160 meter circular array.  I am wondering if anyone
> > has any experience with this model or any other models that
> > work to a range of 100 meters.  (That spec eliminates the vast
> > majority of meters).  How important are accessories like
> > tripods and target cards?
> >
> > 73
> > Rick N6RK
> > _________________
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> Reflector
>
> Roy Morgan
> K1LKY since 1958
> k1lky68 at gmail.com
> Western Mass
>
>
>
>
>
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