I wonder if the 1/4" accuracy at 100' scales (e.g., .025" at 10'), or if
it's always 1/4" (full-scale thing). If it's fixed, it would be too
limiting, but scaled would be plenty good enough.

Bob


If it really uses the laser to measure (as opposed to using the laser to aim a
microwave beam like many do), and according to the diagram on the site it does
indeed appear to use the laser: then the accuracy is probably constant, not
proportional over 100 feet.

It becomes a matter of how accurate the nano-second clock is. The difference in
time between measuring reflected light over 1/4" is .00000000047 seconds, and
you can't build a clock that fast for a few bucks and expect it to maintain
pico-second repeatability under field conditions. So the difference between
measuring the fairly coarse 10 feet or 100 feet isn't the problem area, it's
the float of the timer on that 10th decimal point.


--
Dennis