Parallelism on rotors can be measured using a dial indicator, a laser alignment system, or a straight edge. A dial indicator is used to measure the difference in height between two points on the rotor. A laser alignment system is used to measure the parallelism of the rotor by measuring the distance between two points on the rotor. A straight edge is used to measure the parallelism of the rotor by placing it on the rotor and measuring the gap between the straight edge and the rotor.
