Great Planes AccuPoint Laser Incidence Meter - GPMR4020 - Manual (Page 6)

6
In practice most modelers do not check the stab incidence relative to the datum line.
Instead they use the stab as the reference point for checking the other angles.
Most aircraft manufacturers note the incidence angles on their plan sheet, making it
easy to find the correct incidence angle specifications for your airplane.
1. Attach the meter to the stabilizer (or other reference line). It is common practice to
turn on your radio system so that your servos will hold the surface at neutral. If you
are worried about incidence inaccuracies caused by the elevator being off center, set
the bar across the stabilizer and hold it flat against the surface. This works with flat
slab stabilizers only.
2. Calibrate the meter to the manufacturer’s stab incidence specification.
Checking Wing Incidence