It is well known that, the useful measuring range of a conventional pa
rallel-wire depth probe is restricted by the wire diameters and the sp
acing between the two wires. This paper presents a new probe design in
which the useful measuring range can be extended by introducing an ob
stacle in between the wires. The investigation found that the useful m
easuring range of the probe can be extended by about 30% by introducin
g an additional slotted cylinder in between the two wires.