SKF TKBA 10 Mode D'emploi page 14

Figure 8 Parallel misalignment as found and after correction
If Steps 1, 2 and 3 are followed then the alignment of the belt drives should
be completed quickly. However, one alignment correction may affect other
alignment conditions. Steps 1, 2 and 3 may need to be repeated until the
system is completely aligned.
Good alignment is achieved when the laser lines on the transmitter and
reflector units coincide with the reference lines.
Figure 9 Pulleys perfectly aligned
Note: When tightening the belt, check the horizontal angle alignment and
adjust if necessary.
WARNING: Switch OFF the transmitter unit and remove both units
BEFORE starting machinery.
12 SKF TKBA 10 & 20