How to Locate Non-Metallic Ducts and Pipes Using Ritelite Traceable Duct Rods

Locating underground ducts and pipes is an essential part of many installation, inspection and maintenance tasks. However, plastic and other non-metallic ducts cannot normally be detected using standard cable locating equipment because they do not conduct an electrical signal.

This is where traceable duct rods provide an effective solution. By introducing a conductive element into the duct, engineers can trace the position of the rod from above ground using a signal generator and cable locator. This makes it possible to identify duct routes, locate blockages and confirm the position of underground infrastructure without excavation.

Ritelite’s Cobra range of traceable duct rodding systems offers two different methods for locating non-metallic ducts and drains, providing flexible solutions for contractors working in telecommunications, utilities, drainage and civil engineering.

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Why Non-Metallic Ducts Are Difficult to Locate

tracing non metallic ducts using rod Traditional cable locating equipment works by detecting electromagnetic signals carried along conductive materials such as metal pipes or electrical cables. Plastic ducts, fibre conduits and many drainage pipes do not conduct these signals, which makes them extremely difficult to locate once buried.

Without a traceable element, locating these types of ducts often requires excavation or visual inspection methods. Traceable rodding systems solve this problem by introducing a conductive rod into the duct, allowing a signal to be transmitted and detected from the surface.

When connected to a signal generator such as a CAT and Genny or other cable locating transmitter, the rod can be detected with a cable locator receiver above ground, typically at depths of up to around 3 metres depending on ground conditions.

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Sonde vs Traceable Rod – Understanding the Difference

A common misunderstanding when locating non-metallic ducts is the difference between a sonde transmitter and a traceable rod.

Although both methods allow underground detection, they perform slightly different tasks.

Method What it does
Sonde Allows the operator to locate the exact position of the rod tip
Traceable Rod Allows the operator to trace the full route of the duct
Combined System Enables both route tracing and end-point detection
A sonde is typically used when engineers need to pinpoint a specific point within the duct, such as the location of a blockage or inspection camera. Traceable rods, on the other hand, allow the entire route of a duct to be traced as the rod progresses through the pipe.

Many modern systems combine both methods to provide maximum locating flexibility.

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How Traceable Duct Rod Systems Work

Traceable duct rods contain conductive copper wires embedded within the fibreglass rod. When the rod is connected to a signal generator, a detectable signal is transmitted along the rod.

A cable locator receiver can then detect this signal from above ground, allowing operators to:

  • Trace the route of underground ducts
  • Identify changes in direction
  • Locate blockages or restrictions
  • Map the position of non-metallic pipes and conduits

Because the rod physically travels through the duct, the detected signal accurately represents the position of the duct itself.

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Two Methods of Duct Locating with Ritelite Cobra Traceable Rod

Ritelite manufactures two types of Cobra traceable duct rod systems, each designed to suit different locating requirements.

Quick Trace Cobra rods – provide traceability for a standard duct rodding system

Flexitrace systems – dedicated continuous trace systems with multiple detection modes

The diagrams below illustrates how these two methods of duct locating operate.

Quick Trace Cobra rods
Quick Trace - Method
Flexitrace systems – Sonde Mode
Trace - Sonde Mode
Flexitrace systems – Line Mode
Trace - Line Mode
Both systems are designed specifically for locating non-metallic ducts and drains and are compatible with industry standard cable locating equipment.
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Quick Trace Cobra Duct Rod System

Cobra - Quicktrace The Quick Trace system adds traceable functionality to a standard Cobra duct rodding system. This allows contractors to carry out normal rodding tasks such as installing draw ropes, inspecting ducts or clearing blockages while also enabling the rod to be located underground when required.

When connected to a signal generator such as a 33Hz CAT and Genny system, the copper conductors within the rod allow the full length of the rod to be traced from above ground. This makes it possible to follow the route of the duct as the rod progresses through the pipe.

For enhanced detection in challenging conditions, Quick Trace rods can also be fitted with a sonde, providing a stronger signal at the rod tip and allowing the end point to be located more precisely.

Because Quick Trace can operate both as a standard duct rod and as a traceable locating system, it offers a versatile solution for engineers who require equipment capable of performing multiple tasks on site.

Typical specifications include:

  • Rod diameters: 6mm, 9mm and 11mm
  • Lengths from 30m to 300m
  • Compatible with industry standard 33Hz CAT and Genny locating systems
  • Full length trace detection when connected to a signal generator
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Flexitrace Continuous Trace System

Cobra - Flexitrace The Flexitrace continuous trace system is designed specifically for duct locating and detection applications. Unlike standard rodding systems, Flexitrace provides continuous traceability during both deployment and retrieval, allowing operators to monitor the position of the rod as it moves through the duct.

Flexitrace systems combine two locating technologies in one system, allowing engineers to select the most appropriate detection method for the task.

Sonde Mode

In sonde mode, the integrated sonde end fitting allows operators to locate the exact position of the rod tip. This is particularly useful when identifying blockages or locating the end point of a duct.

Line Mode

Line mode allows the operator to trace the entire length of the rod as it travels through the duct, making it possible to map the route of underground pipes and conduits.

Trace Line Mode

Trace line mode combines the advantages of both detection methods, allowing operators to follow the duct route while also identifying the end position of the rod.

Trace - Sonde Mode Trace - Line Mode
Flexitrace systems are typically available with:

  • Rod diameters: 4.5mm and 6mm
  • Rod lengths from 20m to 150m
  • Continuous trace functionality during deployment
  • Compatibility with 33Hz CAT and Genny locating systems
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Typical Applications for Traceable Cobra Duct Rods

tracing non metallic ducts using rod Traceable duct rods are widely used by contractors working in industries where underground ducts and pipes must be located without excavation.

Common applications include:

  • Locating underground telecommunications ducts
  • Tracing fibre optic conduit routes
  • Identifying blockages in plastic drainage pipes
  • Supporting CCTV drain inspection systems
  • Mapping non-metallic utility infrastructure
  • Confirming duct routes before excavation works

Because they combine mechanical rodding capability with electronic detection, traceable duct rods provide a practical solution for many underground inspection and installation tasks.

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Choosing the Right Cobra Traceable Rod System

Both Quick Trace and Flexitrace systems provide effective solutions for locating non-metallic ducts, but each is suited to slightly different applications.
Feature Quick Trace Flexitrace
Works as standard duct rod Yes No
Full route tracing Yes Yes
Sonde end detection Optional Integrated
Rod diameters 6 / 9 / 11mm 4.5 / 6mm
Rod lengths 30–300m 20–150m
Best suited for Multi-purpose rodding and locating Dedicated locating applications
Selecting the correct system will depend on the type of work being carried out, the duct size and the level of detection required.
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Explore Ritelite Cobra Traceable Duct Rod Systems

Ritelite manufactures a complete range of Cobra traceable duct rodding systems, designed and built in the UK for demanding field environments.

Explore the full product ranges:

Quick Trace Cobra Duct Rod Systems

Flexitrace Continuous Trace Systems
Cobra Duct Rods
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