Cable Avoidance Tools, often called C.A.T scanners or CATs, are commonly used to detect underground services before digging. They are also used during routine survey work to help trace service routes and build a clearer picture of what may be below ground.

Radiodetection is a well-known manufacturer of cable avoidance equipment across the UK and Ireland, with the C.A.T4 and Genny4 range designed for locating buried pipes and cables before excavation.

 

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How does a C.A.T scanner work?

A C.A.T scanner helps detect underground conductive services such as power cables, some telecoms cables and metallic pipes. It is commonly used before excavation, trenching, duct installation, drainage works, fencing, roadworks and general ground investigation.

In simple terms, the scanner helps identify signals from buried services so the operator can mark likely service routes
on the ground.

A C.A.T scanner is not a guarantee that every service will be found. Site conditions, service material, depth, signal strength, operator technique and whether a transmitter is used can all affect results. That is why cable avoidance should be part of a wider safe digging process, not a tick-box exercise.
 

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C.A.T4 vs C.A.T4+ vs gC.A.T4+

Radiodetection’s C.A.T4 range includes several model variants. This guide focuses on the three commonly compared options: C.A.T4, C.A.T4+ and gC.A.T4+.

All three models include core locating modes such as Power, Radio, Genny signal locate and Avoidance Mode. Avoidance Mode searches for Power, Radio and Genny signals at the same time, helping speed up pre-dig scanning.
 

Feature	C.A.T4	C.A.T4+	gC.A.T4+	What it means
Avoidance Mode™	✓	✓	✓	Searches for Power, Radio and Genny signals at the same time to speed up pre-dig scanning.
Genny™ signal locate	✓	✓	✓	Detects locate signals produced by a compatible Genny transmitter.
Power signal locate	✓	✓	✓	Detects signals from power transmission networks.
Radio signal locate	✓	✓	✓	Detects radio signals that may be re-radiated by buried conductive services.
Dynamic Overload Protection	✓	✓	✓	Helps the locator operate in electrically noisy areas.
Depth estimation	✗	✓	✓	Provides an on-screen estimated depth reading, typically in metres on UK/Ireland models, when used correctly with a suitable signal.
StrikeAlert™	✓	✓	✓	Warns the operator of shallow buried cables.
Service Due Indicator	✗	✗	✓	Helps alert users when the instrument is approaching or beyond its service due date.
SWING™ Warning	✗	✗	✓	Warns the operator when poor sweeping technique may affect locate accuracy.
CALSafe™	✗	✗	✓	Can help prevent use of the instrument beyond its calibration or service period.
C.A.T operation logging	✗	✗	✓	Adds positional data to the internal logging system
Bluetooth®	✗	✗	✓	Bluetooth Low Energy connectivity to Android and iOS devices
GPS/GNSS	✗	✗	✓	Built in Data logging and GPS/GNSS receiver enables usage and location analysis and reporting
C.A.T Manager PC support	✓	✓	✓	Allows compatible device management and reporting through C.A.T Manager software.
C.A.T Manager mobile app support	✗	✗	✓	Supports mobile app integration for compatible gC.A.T models.

 

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Choosing the Right Model

The right C.A.T scanner depends on how you plan to use it.

For a small contractor doing occasional shallow excavation, a basic avoidance tool may be enough. For surveyors, utility contractors or companies working across multiple sites, extra features such as depth estimation, data logging, GPS/GNSS and calibration controls can be much more valuable.


The main question is not “Which model has the most features?”
It is: What level of information, control and reporting does your work actually need?


    
   
 

Which C.A.T Scanner Should You Choose?

Here is the practical answer.

Choose the C.A.T4 if you need basic avoidance

The C.A.T4 is suitable where the main requirement is scanning before excavation. It is a sensible option for basic site checks, but it does not give depth estimation or advanced reporting features.


Choose the C.A.T4+ if you need depth information
The C.A.T4+ is a better choice where you want to locate and trace services with more confidence. The depth estimation feature can help with planning, but it should always be treated as an estimate and checked against safe digging practice.


Choose the gC.A.T4+ if you need records, GPS and management features

The gC.A.T4+ is the best option where utility locating is part of regular site operations, survey work or contractor management. GPS/GNSS, Bluetooth, data logging and calibration management features make it more suitable for businesses that need traceability.