Structured wiring specialists test to confirm cabling is properly connected and operating to specifications. It is often necessary to trace a cable’s route, as well. A tone and probe kit is the tool for that job. It can trace wires inside walls, under floors and above ceilings. In security systems work, tone generators are useful for managing pre-existing alarm wiring.


Toners and probes effectively determine the routing of cabling and verify that cables are connected properly, said Harvey Trager, tools product manager at Fluke Networks, Everett, Wash.


“They are useful for installation, troubleshooting new construction, and for adds, moves and changes,” he said. “Advanced models can be used to determine if the cable is wire-mapped properly and even whether the cable or part is connected to an ethernet switch.


“Tone and probe sets often are considered an essential tool for datacom techs. On-premise techs, installers, contractors and outside plant personnel normally have one in their personal toolkit or in the truck. It also is common to see a tone probe hanging on a distribution panel in a wiring closet, in case a tech forgot to bring one,” Trager said.


Fluke Networks offers two tone and probe kits. The Pro3000 Analog tone and probe features SmartTone technology to positively identify wire pairs by changing tone when they are momentarily shorted. Connecting with angled bed-of-nails and RJ-11 connectors, the tone can be sent up to 10 miles. A large loudspeaker can be heard through drywall, wood or other enclosures to find wires quickly and easily.


The second, the advanced IntelliTone Pro 200 LAN tone and probe, has two signaling modes. The digital mode can trace and locate data cabling on active networks while rejecting noise and false signals and can isolate cables in a bundle, despite cable bleed. Analog mode isolates individual wire pairs and can trace voice, audio and video cabling. RJ-45 wire-mapping identifies common wiring faults and verifies ethernet service.


Both tools are for low-voltage cabling only.


Feras Khouri, the voice/data/video (VDV) product manager at Greenlee, Rockford, Ill., said tone and probe kits generally are used to find one or a pair of wires among a bundle or cable containing many wires.


“Certain kits may offer extra functionality, such as continuity testing, polarity, multiple tones and LED signal indicators,” he said. “These tools are used to identify wires for troubleshooting, maintenance and during the initial construction for any application where a wire has to be located or identified. Every technician should carry a tone and probe kit; these are inexpensive and extremely valuable tools.”


Buyers should make sure to purchase units with powerful toners and precise probes.


“Many inexpensive kits may work during an in-office demo, but, when used on real wire, the signal ‘jumps’ to other wire or does not carry its strength over a long wire, making the tone hard to pick up,” Khouri said. “Depending on the environment and application, buyers should consider specialized kits, especially filter probes. Some kits have voltage protection; others do not. This is an important feature.”


Greenlee offers a variety of general purpose and specialized tone and probe kits ranging from the basic 601K-G, through the 701K-G, to the premium 801K, which includes a patented filter probe (200FP). Specialized kits focus on CATV, digital LAN, security/alarm and more.


John Payne, director of hand tool product test and measurement at Southwire Tools, Carrollton, Ga., said tone and probe kits can trace cables behind walls and are sensitive enough to identify individual conductors, including data, phone, video, alarm, audio and power.


“Tone and probe kits are relatively low in cost, so every installer and maintenance tech can carry his or her own,” Payne said. “However, they should not be used with active data cables and never be connected to live [alternating current] circuits.”


Southwire offers the T100PK professional tone and probe kit and T200K, a self-contained kit for tracing a variety of cable types.


Kits include a belt-mounted case with adapter cables, tone generator and probe, LED flashlight for cable tracing in low-light areas, and audible and visible tone indication. Five adapter cables store in the case and plug into the RJ-11 jack on the tone generator.


When evaluating tone and probe testers, Payne identified important features to look for, including multiple tone capability to identify more than one cable in a location, one that changes tone when wires are shorted, stereo headphone jack, rear-facing speaker, LED signal strength indicator, angled bed-of-nails alligator clips for fast connection without striping wires, on-board test lead storage, built-in flashlight, an ergonomic design with a comfortable grip, and a design that allows easy removal from the case without snagging leads.


Sean O’Flaherty, director of product management at Klein Tools, Lincolnshire, Ill., discussed how tone and probe tools work.


“The tone generator modulates an electrical signal on the wire or wires to which it is connected and the probe is tuned to ‘listen’ so that the signal can be traced along a bundle of mixed, loose, unlabeled wires to find the wires that have been connected to the tone generator,” he said. “For example, a tone generator could be connected to a specific wall jack, and the technician may then scan all unlabeled wires in the closet to correctly identify which wire is sourced from that specific wall jack. Typically, individual crew members would carry their own tone and probe instrument, as this is a ubiquitous tool required for everyday applications.”


Klein Tools offers two tone and probe kits: The TraceAll and the ToneCube and ProbePlus Kit.


The TraceAll is a general-purpose tool for the basic tone and probe application—toning the wire with a tone generator and tracing the toned wire with a probe. The product is sold as a stand-alone complete system, and the tone generator stores in the probe handle when not in use. An RJ-11 jack on the tone generator allows it to connect to common telephony cabling, and the system also comes with a jumper cable with alligator clips to connect to other types of cabling systems.


The ProbePlus and ToneCube Kit is a professional cable installer’s tool used to trace wire paths and identify cables in any common wiring systems. The ToneCube tone generator can tone wires with five different tone styles and connect to a wiring system through a universal connector compatible with RJ-11/12 and RJ-45 architectures or with alligator clips that are hardwired into the tone generator. The tone generator also can perform other industry standard systems tests.


“Technically, these tools could be used on wires for either low-voltage or high-voltage installations,” O’Flaherty said. “However, many of these tools can only be used on dark cables. A tone generator never should be connected to circuits connected to the electrical main supply unless the instrument has been specifically designed for such a purpose. In these cases, the instrument also should bear an appropriate category safety rating appropriate for the type of circuit to which it is being connected.”