Cable and pipe locating

How does a cable locator work?

Cable locators detect the electromagnetic fields of utility lines, thereby revealing hidden routes. In passive mode, the device uses existing fields – such as the 50/60 Hz mains frequency or broadcast signals. In active mode, a signal generator injects a defined frequency directly into the line, making location considerably more precise and selective. In addition, sondes that emit their own signal can be located.

Frequencies & application profiles

Choosing the right frequency is decisive for the locating result. Depending on depth, line length and environment, different frequency ranges are suitable:

• Low frequencies (e.g. 512/640 Hz, 1 kHz): for greater depths and directional location with low propagation
• Medium frequencies (e.g. 8–9 kHz): well-balanced for mixed environments
• Higher frequencies (e.g. 33 kHz): versatile, with good coupling to short or interrupted conductors

Selection guide: finding the right cable locator

Which cable locator suits you depends primarily on the intended application. The following criteria will help you decide:

• Application: construction site search, route tracing, house connection, fault & repair
• Frequency package: select suitable active and passive frequencies as well as sonde mode
• Signal generator power: sufficient for line length, depth and earthing situation
• Functions: depth indication, current measurement, directional guidance, data logging
• Accessories: signal clamp, earth stakes, A-Frame for ground faults, connection & search cables

Practical tips for cable location

• Always check in several modes (passive & active) before excavation
• Close the signal path: ensure good earthing or grounding
• Locate the route in sections and document the readings

Frequently asked questions about cable locators

What is the difference between active and passive?

In passive mode, existing fields are used, whereas in active mode a definable signal is injected via a generator – this increases precision and selectivity.

Can I also find non-metallic lines?

Indirectly, if a tracer wire is present or a sonde is used. Pure plastic pipes without a conductor require a sonde or a tracer.

How accurate is the depth indication?

Accuracy depends on signal quality, ground conditions and alignment. Clean coupling and correct device settings improve the result.

Which frequency is the right one?

Low frequencies are suitable for deep, long, well-earthed conductors; 8–9 kHz for mixed environments; 33 kHz for short or interrupted conductors.