Cable Fault Pinpointer Acoustic Magnetic Synchronous 0.1m Accuracy for Telecom Coaxial Cable Faults | XHDD503B

The XHDD503B cable fault pinpointer locates the exact fault point of buried telecom and coaxial cables after a pre-locator has delivered the rough distance. Using acoustic-magnetic synchronization, it detects the discharge sound from the fault through a sensitive ground probe and simultaneously receives the magnetic field pulse; the instrument automatically computes the acoustic-magnetic time difference and shows the waveform on a 5-inch touch LCD. The fault sits where the time difference is smallest and the discharge sound is loudest, typically within 0.1m, even for high-resistance leakage and flashover faults.

• Pinpoints low-resistance, open / disconnection and high-resistance faults of buried coaxial and communication cables to ≤0.1m
• Acoustic-magnetic time-difference readout removes dependence on operator hearing in traffic-noisy streets
• Four filter modes separate the discharge sound from urban background noise; band pass 200-600Hz is the practical default
• 8-level gain and 0-99 trigger threshold per channel shield weak interference and capture only real discharge pulses
• Sunlight-readable 5-inch touch LCD is easy to read at roadside cabinets and manholes in any weather
• IP65 sensor with multi-layer physical isolation works reliably in dust, rain spray and humid cable chambers
• More than 8 hours continuous operation from 4 x 18650 cells covers long distribution-network campaigns
• Headphone output up to 112dB with 350Ω impedance gives clear monitoring even beside busy roads

Discharge sound changes as it travels through different ground cover. Hard coverings such as cement and stone slabs pass high frequencies well; soft soil and sand absorb them, leaving mostly low-frequency energy. The XHDD503B therefore offers four selectable filter modes, and the right choice shortens the pinpointing job significantly:

Two-pass search method: In the first pass, set a low trigger threshold, high gain and high volume, walk the probe along the cable every 1-2m and monitor at least two discharge cycles per point, noting where sound, waveform and time difference peak. In the second pass, come back with a higher threshold, lower gain and lower volume, and mark the point where the sound is loudest and the acoustic-magnetic time difference is smallest - the overlap is the fault point.

• Watch the four acoustic-magnetic time-difference readings on screen; the value decreases as you approach the fault and increases again past it
• The magnetic channel also confirms you are near the cable path, which helps reject false signals
• Do not place the sensor directly on the cable body: large discharge currents cause electrical-stress vibration along the whole cable, producing a weak "pop" everywhere that must not be mistaken for the fault
• A faint tapping heard along the entire route that does not change with sensor position is electrical-stress vibration, not the fault discharge