ABSTRACT
The purpose of the sensor is to obtain dimensional information from the workpiece. The sensor itself is key to the concept of closed-loop control since it must measure the desired parameter, an ancillary one, and it must do so with the sensitivity needed for the degree of control or accuracy required. In-process sensors for batch manufacturing can be broken down into two major categories: contact and noncontact. Non-contact sensors have come into greater favor because the lack of contact eliminates wear and deflection, which introduce inaccuracy into the measurement. A great variety of dimensional measurement sensors can be used successfully in an in-process application. The reader should be aware, however, that no one sensor is suited to all applications. The physical size of the sensor is important because it determines how close the sensor can be to the desired point of measurement.
