Using a C.A.T4

Follow Avatar Anthony Caplin
Updated : Created :
In this article


Grip the handle. Press and hold the trigger and listen for the bleep indicating the batteries are OK. Replace both batteries if there is no bleep or if the battery icon is flashing.

eC.A.T4 and gC.A.T4 models only

eC.A.T4 and gC.A.T4 units perform a self test at startup to check for logging system errors. If a problem is detected the unit will momentarily display the message error 2 iconand sound a warning audio tone.

NOTE: The internal data logging system will not work properly if the message error 2 iconhas been displayed. Please return for immediate service.

If required eC.A.T4 and gC.A.T4 can automatically be disabled if an error 2 iconwarning is detected.

Refer to the C.A.T Manager manual for further information.

When a service/calibration is due in 31 days or less, the screen will display 'CAL' at startup, followed by the number of days until a service/calibration is due.


CAL icon CALSafe

CALSafe enabled units are equipped with a system which does not permit them to function once they are beyond the expected service/calibration date.

IfCAL iconflashes continually on startup, immediately return your C.A.T for service/calibration.


Do not attempt to use a C.A.T4 for tracing pipes or cables outside its calibration period. If in doubt, contact the person responsible, or Radiodetection.


Select Mode

C.A.T4 models are equipped with four locate modes:

Avoidance mode icon Avoidance Mode A for Avoidance mode: detects all locate signals simultaneously, including Genny, Power, and Radio signals. The sensitivity control adjusts the Power, Radio and Genny signal levels simultaneously.
Genny mode icon Genny Mode G for Genny: detects the locate signals produced by a Genny. There are various ways of applying the Genny signal. Using a Genny is the most reliable way to detect a pipe or cable. The C.A.T4 and Genny4 feature new locate signals that make the combination more sensitive to small core cables (e.g. telecoms & street lighting).
Power mode icon

Power Mode P for power: detects signals originating from power transmission networks. These signals may be found on any pipe or cable, not just power cables. 

Some power cables DO NOT radiate detectable power signals.

Power signals may not be found on power cables that are switched off (e.g. a street light cable during daylight hours). Always use a Genny before excavating.

Radio mode icon

Radio Mode R for Radio: detects radio signals originating from distant radio transmitters as they travel along underground pipes and cables.

Radio signals are not always present. Always use a Genny before excavating.



Hold the C.A.T4 with the blade vertical and with the lower edge just above the ground. Do not swing the C.A.T4 or tilt it more than a few degrees from the vertical. Swinging the C.A.T will affect locate accuracy; all eC.A.T4 and gC.A.T4 models feature SWING, a sensing device to remind operators to use the C.A.T correctly.

Locating cables and pipes

The sensitivity control is used to narrow the field in which the C.A.T4 can locate a pipe or cable. The sensitivity control should be set to maximum before beginning to locate.

In all locate modes the bargraph and sound levels increase as the C.A.T gets closer to a pipe or cable, and reduce once it passes beyond it or as it gets further away.


As the bargraph readout passes maximum over a pipe or cable, turn the sensitivity control down and move back over the locate position. By repeating this process back and forth across the maximum readout position, the cable or pipe’s position can be pinpointed. The tidemark feature hold the maximum bargraph reading to ease identification of a peak readout.

If the position cannot be easily determined using Avoidance Mode, switch between the dedicated locate modes (Genny, Power or Radio) before adjusting the sensitivity control to pinpoint the cable or pipe.

Determining a cable or a pipe's direction

Once a cable or pipe’s position has been pinpointed, rotate the C.A.T4 above it. The C.A.T is at right angles across the cable or pipe when the bargraph and audio are at a maximum, and is directly inline with it when the bargraph and audio are at a minimum. Check for accuracy by varying the sensitivity control while rotating the C.A.T. (This process can be less precise in Power Mode because of the nature of detectable power signals).


rotate the C.A.T


Trace the buried conductor keeping the C.A.T4 vertical and moving it steadily from side to side. Follow the line of the buried conductor, marking it as required across the area to be excavated.

Scanning an area before digging

An initial sweep using Avoidance Mode is recommended, followed by detailed scans using the other modes. Use the Genny mode for Depth estimation once a pipe or cable has been detected (C.A.T4+, eC.A.T4+ and gC.A.T4+ only).

Turn the Function Switch to Avoidance mode icon (Avoidance Mode) to sweep the area for cables or pipes radiating Genny, Power or Radio signals. Turn the sensitivity control to maximum before starting. If the signal bargraph does not move from maximum, reduce the sensitivity control so that the bargraph is below half-way before starting.

Sweep the area to be excavated with a steady and deliberate motion.

Begin by walking the perimeter of the proposed excavation site. Then walk the length of the of the excavation site, moving across the width in parallel sweeps around 0.5 metres apart. If using a Genny in induction mode, position the Genny as shown so that the chevrons on the C.A.T4 are inline with the chevrons of the Genny4.

Then sweep across the width of the excavation site, moving up the length. If using a Genny in induction mode, position the Genny as shown.

If a cable or pipe is located, first establish the direction of the cable or pipe, then trace it across the area to be excavated, marking if required.

Then resume sweeping over the excavation site.

active sweep in induction mode


Active search using Induction - finding parallel pipes and cables

Placing the Genny4 on its side swamps an area with Genny signal. Note that signal is not transmitted directly below the Genny4 in this orientation, so repeat the exercise with the Genny4 moved to the side by at least 1m. Alternatively, use a two man technique to search an area for buried utilities as shown.

Genny placed on it's side


the 2 man sweep technique


Eliminating adjacent cables or pipes ('Nulling out')

In some applications a cable or pipe carrying a signal can mask adjacent utilities. For example, a large locate signal could be flowing along a large cable that is running close to a second cable with a smaller signal. In this situation C.A.T4 can be expected to locate the signal from the larger cable but may not locate the second cable. To locate the second cable carry out the following:

  1. Using the Genny4 in induction mode, place the Genny4 on its side directly over the large cable, and in-line with its direction as illustrated.
  2. The cable beneath the Genny4 should now have no locate signal transmitted to it, but other cables in the vicinity should have the Genny signal transmitted to them and may now be located with the C.A.T4.

Genny on it's side


Estimating line depth using the C.A.T4+/eC.A.T4+/gC.A.T4+ and Genny4

Do not use the C.A.T4+, eC.A.T4+ or gCAT4+ depth estimation function to decide if mechanical digging is appropriate.

Depth estimations are only possible when using the C.A.T4+, eC.A.T4+ or gC.A.T4+ in Genny mode.

If using the Genny4 in induction mode, ensure that the depth estimation position is at least 10m from the Genny. If using direct connection or a signal clamp, this distance can be reduced to approximately 5m. Once a cable or pipe has been located, position the C.A.T above its position and at right angles to its direction.

10m distance illustration


Press and release the depth button. The display will show the estimated depth to the detected conductor.

Do not estimate depth near a bend or tee in a cable or pipe.



All C.A.T4 models incorporate Dynamic Overload Protection, a powerful signal processing tool that identifies and automatically rejects electrical interference that may otherwise overload the C.A.T’s electronics. Dynamic Overload Protection allows the operator to locate pipes and cables in electrically noisy environments such as near power sub stations or near overhead high-voltage cables. Note that Dynamic Overload Protection will not overcome very high levels of interference. In this situation the Signal Overload Warning will appear (see Warnings).