An electronic measuring device is disclosed which includes a pair of
wheels connected to an axle that passes through a drive gear. The drive
gear is enmeshed to a second gear which, in turn, is coaxially connected
to an encoder disk. The encoder disk has spaced-apart fins around its
outer periphery. As the wheels turn and the encoder disk rotates, the
fins and openings between the fins pass between an emitter and a
receiver. The emitter and receiver are linked to a controller which
calculates the distance traversed by the wheels based upon the number of
fins that pass between the emitter and receiver, or with an active
counting system (ACS). The controller also includes functions to
establish start and stop points for a measurement and an easy means for
dividing a measured distance into equal parts or segments and a means for
marking the boundary points that define the segments when the measuring
device is rolled back across the measured distance. The device can be
used on both planar and non-planar surfaces.