DEVICE FOR DETERMINING THE LENGTH OF A SET OF BORING RODS

摘要

The invention relates to a device for determining the length of a set of boring rods comprising a plurality of pipes (1) assembled by couplings (2). Said device is characterised in that at least one electrical line (3, 4) galvanically connected to the couplings (2) is arranged along the pipes (1). A device (7) for feeding electrical impulses into the electrical line (3, 4), and for determining the time taken for the electrical impulses to travel from the device (7) to a reflection point on the other end (5) of the electrical line (3, 4), and back, is arranged on one end of the electrical line (3, 4).