The Sensors
The function of a Co-ordinate Measuring Machine (CMM) is the acquisition of information on the measurand; generally under form of Cartesian co-ordinate values. The devices utilised to explore the part in order to generate such information are the „Sensors“; as underlined in the 1st article one of the four fundamental components of a CMM. The sensor technology has gone through a remarkable evolution in the last 25 years; today are therefore available a number of solutions, which allow to solve any application problem. The difference between sensors, besides the mere metrological characteristics, is due to the physical principle on which they are based. The first discrimination derives from the method by means of which the sensor allows to gather information on the part to be measured; consequently there are two important families of the devices in question:
1. "Tactile“ sensors.
2. "Non contact“ sensors, or "Optoelectronic“ sensors.
