Method and system for measuring an opening at least partially defined by a surface. A plurality of target bodies are positioned about a circumference of a target body holder that is sized to fit within the opening. The target bodies are forced radially out...

The beam source, a laser or white light source, and its receiver unit are so constructed and matched with each other, that spectral separation of the beam is effected. The source may emit at two different wavelengths and comprises two lasers operating at d...