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.