FIELD: measuring technique, possibly in machine engineering, mainly for measuring parameters of spline grooves of shafts. SUBSTANCE: apparatus includes housing in the form of prism supporting measuring unit with measuring probe. Prism supports indicator with measuring stem and rod mounted with possibility of engaging with measuring stem and with possibility of rotation around its own lengthwise axis and reciprocation motion along said axis. Rod supports probe that may engage by its lateral surface with lateral surfaces of measured groove. Prism has slot matched with working surfaces of prism and arranged along bisector plane of prism with possibility of introducing probe inside it. Lateral working of probe is spherical one and it may be centered according to working surfaces of prism. EFFECT: enhanced efficiency and accuracy of measurements. 3 dwg
