Abstract: A dial indicator for accurately measuring displacement of a part along a measurement axis. The dial indicator includes scale electrodes of a given pitch and reader stationary scale electrodes of a given pitch. A reader carries a plurality of reader bars having a pitch of one half that of the scale electrodes. A set of drive signals of a given frequency are applied in different ways to the scale bar electrodes to achieve coarse and fine positions of the reader relative to the scale. One operating mode involves determining the position of the reader 34 with a coarse measurement relative to the scale, and a fine measurement. These signals can combined to obtain an accurate position over the reader and position of a spindle reading displaced.
Abstract: A dial indicator for accurately measuring displacement of a part along a measurement axis. The dial indicator includes scale electrodes of a given pitch and reader stationary scale electrodes of a given pitch. A reader carries a plurality of reader bars having a pitch of one half that of the scale electrodes. A set of drive signals of a given frequency are applied in different ways to the scale bar electrodes to achieve coarse and fine positions of the reader relative to the scale. One operating mode involves determining the position of the reader 34 with a coarse measurement relative to the scale, and a fine measurement. These signals can combined to obtain an accurate position over the reader and position of a spindle reading displaced.