APPLICATION NOTE: Laser Triangulation Sensors - MTI Instruments ...

MTII’s laser sensors have through holes that can be used to mount and secure the laser
heads. Fixtures should be made to match the location of these holes and maintain the
laser head perpendicular to the target of interest.
v.) Synchronization
When making differential thickness measurements with 2 laser heads it is important to
take and process measurements from both heads at the exact same time. This is to
eliminate the effects due to vibration. If the target is moving, and measurements are taken
at slightly different times, the processed results may report a slightly thinner or thicker
target. MTII’s Microtrak II line of laser sensors have provisions to synchronize heads
eliminating this problem.
4) Advantages and Disadvantages
i.) Advantages
As with any sensing technology, laser systems have both advantages and disadvantages.
Perhaps their greatest attribute is their ability to resolve measurements below one micron
at a fraction of the cost of other high performance technologies. In addition, their
measurement range is large allowing them to fulfill a variety of application requirements.
The large operating distance provides sufficient standoff to reduce possible damage from
contacting the moving target.
ii.) Disdvantages
As mentioned above, laser sensors should be kept clean. Dirt or other foreign debris can
affect accuracy so frequent cleaning may be required. Because laser heads have sensitive
electronic components their operating temperature is limited and vacuum installations are
not recommended without external cooling.
5) Applications
i.) Position Sensing
General positioning is probably the most common application for laser sensors. Their
fast, highly linear response makes them ideally suited to be applied in both static and
active feedback positioning applications. Large operating distance and measurement
range provides the flexibility for process and quality control monitoring. Typical
applications include:
• Pavement and concrete road profiling
• Railroad track alignment
• Robot location
• Welding head position