Luke M. Snell, P.E.
Images courtesy of author
Construction Around Arizona
Hand-Held Distance Measuring
Equipment
Senior Materials Engineer at Western Technologies in
Phoenix, Arizona and Emeritus Professor of Construction
at Southern Illinois University Edwardsville
F
or most of us, taking a measurement
of an object is simple. We read the
length or width directly from our
measuring tape. When we want to
determine the volume or area, it gets a
little more complicated. We must take the
measurements, get the calculator, enter
the numbers (hopefully correctly), and
calculate the value.
I have been working with a variety of
hand-held distance measuring equipment
for more than 10 years. This equipment is
really a computer that allows you to take
measurements with either a sonic wave or
a laser light beam and subsequently does
the calculations. For those who routinely
measure distances and determine areas
and/or volumes, this can be a major time
saver. The cost of this equipment is as low
as $60.
Principles: The distance measuring
devices calculate the distance by sending
out a sound wave or a laser light beam that
hits a target and bounces back. A timer
measures how long it takes for the sound
wave or laser light beam to travel to the
target and return.
The equipment then calculates the
distance by the formula: D= VT/2, where:
D = Distance in whatever units the user
chooses, V = Velocity of the sound wave or
the laser light beam, and T = Time for the
thirty
sound wave or laser light beam to hit the
target and return.
Sound waves vary by temperature and
have a conical shape. If part of the sound
wave hits any interference, the reading will
be incorrect. The timer in this equipment
is simpler and the cost is lower. I don’t
recommend sonic wave equipment as, in
my research, it has been unreliable.
The laser equipment has a small
narrow light beam that has a consistent
velocity. The user can see the laser light
and detect any interference.
This
equipment has an accuracy of less than +/1/8 inch, which is probably more accurate
than a tape measure.
I strongly
recommend using the laser equipment. Be
careful when purchasing equipment as it
may be unclear whether it uses a sound
wave or laser light.
Range: The biggest question the user
must consider is the distance they will be
measuring.
Hand-held laser distance
measuring equipment that will measure up
to 100 feet costs less than $100. If you
need to measure longer distances, the cost
will increase from $200-$500. Surveying
equipment that measures still longer
distances has a much higher cost.
Procedures: Hand-held laser distance
measuring devices are simple to use and
self-explanatory.
One of the most
important procedures is to determine area
or volume in the unit of choice. The menu
on the equipment will show a square (for
area) or a cube (for volume). If you select
area, the equipment a