DMA-Aero manufacture electromechanical angular protractors to measure the relative rotation between movable surfaces such as aircraft fly-by-wire control surfaces.
Angular position is measured by a goniometric scale and/or by an angular position sensor with 0.01 deg. resolution. Angular protractors can be supplied with two types of fixing plates: the screw-type plate and the suction-type plate. A special bearing on the mounting and a cylindrical hinge allows the protractor to check the relative rotation angle between movable surfaces having a transversal misalignment of 0.8 inch (20 mm) max.
Four models of control units (MAN2B, MAN4B, MAN8B or MAN16B) can be used to read 2, 4, 8 or 16 protractors simultaneously.