PASCO ME-9259A Instruction Sheet

Instruction Sheet for
the PASCO
Model ME-9259A
The PASCO Model ME-9259A Laser Switch is a high
performance photo switch which utilizes a laser (such as
PASCO Models OS-9171 and SE-9367) as a light source. It
is extremely valuable in the following situations.
When the interruption of the photogate is of very short
duration. Since the rise and fall times of the ME-9259A
are on the order of 200 nanoseconds, this Laser Switch
can easily "see" interruptions on the order of 1 micro-
second.
When the photodetector must be located more than a
few inches from the light source. This is necessary if
the object to pass through the photogate is large, or if
the object's trajectory is not easily controllable, or if a
combination of mirrors is to be used to allow one laser
and one Laser Switch to start and stop the timer. See
Figure 1.

Set-Up and Alignment

If the distance between the laser and Laser Switch is 5
m or less, a 0.5 mW laser is probably sufficient.
Beyond 5 m, a more powerful laser must be used.
Align the Laser Switch such that the laser beam is
incident upon the input port at the end of the Laser
LASER SWITCH
MIRROR
MOVING
OBJECT
LASER
Figure 1
Switch. On the tube of the switch, indicated by the
label, is a small green DOT (LED). With the laser beam
aimed down the axis of the tube, align the Laser Switch
such that the DOT lights up as brightly as possible. The
Laser Switch is now properly aligned with the laser.
Caution: Never attempt to align the laser switch
by sighting with your eye. Never look directly into
the laser. Never use a laser with an output exceed-
ing 0.5 mW unless you are wearing laser safety
glasses and the instructor is present.
012-01231C
10/95
$1.00
MIRROR
ME-9259A
LASER SWITCH