How often have you had to ask a customer
to hold the end of your tape
measure while you were scoping out a
job? With an ultrasonic measurer that
reflects sound waves off a distant wall
or ceiling, you may be able to wow that
customer instead. But be careful; these
devices are limited. You can't measure
from the ground to the peak of a gable
end, for instance. The ultrasonic
"beam" must hit square to a surface or
the echo won't be reflected back to the
sensor. Furniture, curtains, or pictures
on the wall can absorb or scatter the
beam, giving an inaccurate measurement
or none at all. Even if you aim
the instrument correctly,