TABLE OF CONTENTS It is difficult to overestimate the impact electronic gaging has made on the field of dimensional measurement in recent years. Advances in the miniaturization of electronic components, the design and manufacture of integrated circuits, and the development of computer hardware and software have touched and changed virtually every facet of metrology now practiced in industry. Therefore, any discussion of modern electronic gages cannot be confined to a single chapter such as this. And as such, electronic gages have been introduced, pictured and discussed within the individual chapters of this handbook. Today, electronic gages are simply viewed as the natural evolution of specific gage types (that is, vernier calipers become digital calipers and mechanical dial indicators became digital indicators). Yet, certain basic electronic gaging principles can and should be discussed in a general way. This chapter will attempt to do so.
In metrology, the term electronic gages comprises a diverse category of measuring instruments capable of detecting and displaying dimensional variations through the combined use of mechanical and electronic components. Such variations are typically used to cause the displacement of a mechanical contacting sensing member in relation to a preset position, thereby originating proportional electrical signals, which are then amplified and indicated. Noncontact methods, covered later in this chapter, can also be used to generate electrical signals. The indicated variation generally appears on the face of either a meter or an LCD (liquid crystal display) analog whose scale is graduated in fractional values of the standard...
