| 摘要 |
A measuring system for localizing a defect spot along a wire or along an insulated pipe having incorporated a wire in its insulation, comprising a pulse generator transmitting to one end of the wire consecutive trains of electric pulses, these pulses in each train being of steadily increasing or decreasing duration, an associated detector receiver for receiving through said wire end pulses reflected from said spot and designed so as to produce a detector signal in response to reception of a reflected pulse front substantially concurrently with the termination of the transmission of the pulse to which said pulse front belongs, and indicator means operable to identify each of the individual pulses in response to occurrence of said detector signal, whereby the duration of the pulse thus identified will be indicative of its running time to and from the defect pulse reflecting spot and therewith be indicative of the distance from the wire end to the spot. Preferably the indicator means is a counter operable to successively count the consecutive pulses, these being generated with a constant predetermined pulse frequency, and to stop or read out the count in response to occurrence of the detector signal, whereby it is possible to produce a direct digital reading of the location of the defect spot. |
