Aligning The Instrument - ABB LLT100 Operating Instructions Manual

LLT100
Laser level transmitter
– For pressure-rated applications, make sure to respect the
national codes and/or certification regulations in terms of
mounting, bolts and gaskets.
– For all types of flanges, tighten the flange bolts in an
alternating crisscross pattern to a torque value of one-fourth
of the final bolting torque. Repeat this procedure four times,
increasing the torque value each time by a fourth of the final
torque value. After applying the final torque value, tighten
each bolt again to allow for gasket compression.

11.7 Aligning the instrument

The instrument lens should be mounted facing directly
towards the area to be measured, with no obstacles directly
in the beam path.
The instrument will work on surfaces that are rough or at an
angle. There is no need to mount the instrument perpendicular
to the material as it will not be affected by the cone up or down
the material.
However, for liquid applications, mount the laser as
perpendicular as possible to the surface. A misalignment of
up to 5 degrees may be acceptable in very good conditions
(short distance, smooth surface, clear light), but the longer the
distance, the more perpendicular the laser must be (no more
than 1 or 2 degrees for optimal performance).
To prevent interference with nearby objects, the instrument
output laser beam was designed as a narrow rectangle (i.e.
8 in × 1.2 in at 100 ft) (see also "Laser" on page 60). The
laser beam is factory-aligned perpendicular to the instrument
flange window (90° ± 0.5°). The long side of the rectangle is
parallel to the blocking screw, as illustrated in Figure 24 on
page 34. This screw is factory-secured and cannot be
loosened.
Locking screw
Figure 24 Laser beam top view (at ±100 ft)
34 User Guide | OI-LLT100-EN Rev.DE
The main point to consider when aligning the instrument is
a clear line of sight. Should there be an obstacle in the laser
beam trajectory, align the obstacle parallel to the beam long
side by using the flange to rotate the whole instrument.
Locking screw
Figure 25 Typical installation (class 150 process flange)
Gasket
Process flange