Abstract: A digital electronic micrometer eliminates backlash and other error between a movable probe and a digital readout and arranges all the working components within a handle thermally insulated from the probe and the yoke. An optical scale is secured to the probe to move directly with the probe past an electro-optical reader arranged within the tool handle, and a manually operable retractor moves the probe away from the anvil against the bias of a spring. Electronic circuitry and digital display can also be arranged in the tool handle for indicating positions of the probe relative to the frame, and the circuitry includes manually actuatable hold circuitry for maintaining the display at an indication of a previous position of the probe after movement of the probe. This allows the tool to be moved to an orientation for observing a measurement previously taken when the tool was in a position obscuring the reading.

Abstract: Apparatus for measuring which is adapted for use with a remote digital readout. The measuring apparatus includes an elongated main beam and a measuring device slidably mounted on the beam. The beam includes a transparent ruled scale with markings positioned thereon corresponding to different measurements. Mounted within the device is an electro-optical decoder suspended by a unique flexure arrangement which detects marks as the device is slidably moved on the beam and produces electrical signals which are provided to the remote digital readout system which in turn produces a visual readout of measurement. The measuring device includes a second reader scale having similar markings thereon.