SM31E Datasheet, PDF (2/8 Pages) List of Unclassifed Manufacturers – Self-contained DC-operated Opposed Mode Sensors

MINI-BEAM^® Sensors SM31E/SM31R and SM31EL/SM31RL
MINI-BEAM Installation and Alignment
Proper operation of the sensors requires that they be mounted
securely and aligned properly. Excessive movement or vibration
can cause intermittent or false operation due to loss of alignment.
For maximum mechanical stability, final-mount these sensors in
18-mm holes by their threaded barrels or use a mounting bracket
(see page 6).
1) Begin with the emitter mounted securely in place. For
small-parts counting applications, stretch a string
between the emitter and receiver lenses to ensure that the
sensing beam will pass through the center of the sensing
location. For less critical applications, the receiver may be
initially positioned by line-of-sight placement. Mount the
receiver, leaving a means for movement.
2) Apply power to the emitter and receiver, and advance the
receiver’s 15-turn GAIN control to maximum (clockwise
end of rotation). The GAIN control is clutched at both
ends to avoid damage, and will “free-wheel” when either
endpoint is reached.
If the receiver is “seeing” the emitter’s light beam, the
receiver alignment LED should be “on”. Move the receiver
up-down-right-left (include angular rotation) to obtain the
fastest receiver LED pulse rate. If a pulse is not
observable (too fast to count), reduce the GAIN control
(counterclockwise rotation) to obtain a countable pulse
rate of one to five beats per second. Note: to aid
alignment at short ranges, it may help to further reduce
the strength of the light signal by temporarily masking
the emitter and/or receiver lens with tape or a sheet of
paper.
3) Repeat the alignment motions after each GAIN reduction.
When you have found the receiver orientation that
produces the fastest pulse rate, mount the receiver solidly
in that position. Remove any masking material, and
increase the receiver GAIN to maximum. Test the system
by placing the object to be detected into the sensing
position. The receiver LED indicator should go “off”. If it
does not go “off”, the cause is probably either “flooding”
or “burn-through”.
Flooding occurs when a portion of the effective beam
passes around the object to be sensed and activates the
receiver. Check that the object completely breaks the
beam, and that the beam is centered on the object. Add
apertures, if necessary, to tailor the effective beam to the
size or profile of the object being sensed. Burn-through
refers to a portion of the emitter’s light energy passing
through a thin or translucent object and activating the
receiver. Try sensing at a reduced GAIN setting or
consider an alternative sensing scheme.
page 2
Emitter
Opposed Mode Alignment
Move receiver to obtain the
fastest LED pulse rate.
Receiver
Up
Right
Left
Down
Receiver
15 Turn
Gain
Adjustment
and Light/Dark
Operate Switch*
Gasketed
Acrylic Cover
“AID” Indicator LED lights when the
sensor sees the reflection of its own modulated
light and pulses at a rate proportional to the
strength of the received light signal
* Note regarding Light/Dark operate switch:
• Turn switch fully clockwise for light operate (sensor
outputs conduct when sensing light is received)
• Turn switch fully counterclockwise for dark operate
(sensor outputs conduct when sensing light is not
received)
Banner Engineering Corp. • Minneapolis, U.S.A.
www.bannerengineering.com • Tel: [phone]