LASER DETECTOR TESTS: WHAT YOU SHOULD KNOW
Speed laser amounts to shaft of faint light, very small
in diameter, spaghetti size as it leaves the gun. A laser detector looks for that faint light. Laser
enforcement is quick, and defending against a light beam
is an iffy proposition. If the detector can’t find the
light before the light finds its target—your car—warning
will most likely be too late. But lasers, like other light,
are reflected off various surfaces—posts and signs, other
cars, the pavement. Moreover, the light gun is aimed by a human. His aim wobbles. At long ranges, he hits a lot of things beside
his target. A good laser detector is sensitive enough
to find these reflections, these aiming wobbles. Remember, though, that the bright section of the
beam is only one-fifth of a degree wide, so testing laser
detectors requires that the beam be positioned, and held
in that position, with great precision.
that must be
light. The brighter the sun, the harder it is to find a faint
laser beam. Even
the sun-to-shade-to-sun variations from passing clouds
will make results non-repeatable.
a potential customer, you’d like to know performance under
the worst conditions—clear sky, high noon—and under the
best conditions—dark of the night, after the sun’s glow
has disappeared from the west.
glass. All glass absorbs some
light, and different windshields use different glass
all testing should be done on the same car, maintaining
the same position on the windshield for all detectors.
3. Car color. A hood painted white or silver reflects much more sunlight than
a black one, to the detriment of laser detection. Again, all testing should be on the same car. Better yet, testing could compare the results of two cars,
one white, one black, so you can see how reflections effect
performance of each detector.
4. Aiming the laser beam. The laser gun must be securely mounted in order
to produce a repeatable point of aim. Remember, the beam is very narrow compared to radar,
practically a rifle shot.
would be a revealing test: With the laser gun in a rigid fixture, aim
the beam straight down the test lane at a spot on the
pavement 500 to 800 feet from the gun. The exact same spot, and unvarying sun, are necessary
to give each detector the same chance at detection. With each detector mounted in a repeatable position
on a test car’s windshield, start well out of range and
drive toward the laser gun. Which detectors find the reflected laser? How far off? Repeat test in bright sun and in dark of night.
detector that can find the reflection has a chance of
providing useful warning. And the earlier the warning, the greater its usefulness.
Radar Detectors Tests... If they don't examine
real customer needs, what's the point?