Photo-optic measuring systems are presently utilized for automatic and continuous measurements of manufactured parts and subassemblies. Measurable parameters are physical dimensions such as bore diameters; flatness and concentricities; surface perturbations, such as microfinish, seams, pits and scratches; and finally, mechanical defects, such as cracks, mislocations, or unusual gaps in assemblies. The basic unit of these systems is the bifurcated fiber-optic probe which scans the surface of the object in question. The probe assembly utilizes reflected light from the object returning via the fiber optics to the detector for generation of the information signal. The information signal is processed electronically to yield the required values. The measurement is accomplished then in milliseconds instead of seconds.