The device consists of a slider (2) operating in a sliding manner with respect to a ruler (1). Slider (2) is fitted with emitting electrodes (10) and receiving electrodes (19,20) connected to an electronic assembly (50). Ruler (1) is provided with L and inverted L-shaped coupling electrodes (6,7) which interlock mutually to form electrode-pairs which position is limited by straight lines. The vertical parts of the L's (40) are arranged to face emitting electrodes (10), whereas the horizontal parts of the L's (41) are arranged to face the receiving electrodes (19,20), providing an optimal capacitative coupling. This arrangement of the coupling electrodes (6,7) makes it possible to obtain a precision type manufacture of the ruler and a side by side (juxtaposition) arrangement of several rulers to fit the measuring needs. |