Utility Locating

RD7200 by Radiodetection

Locating utilities is a crucial process that ensures safety and efficiency during construction, excavation, or landscaping projects. Below are some common methods and technologies used for utility detection. Concrete Imaging can locate buried piping through various techniques, including passive, induction, and direct line tracing.

We utilize Radiodetection's RD7200. This system features a multi-function passive locating feature that enables us to identify the electrical fields generated by buried electrical conduits. Using this equipment, we can provide the location, direction, and approximate depth of the pipes.

If we can access a metal pipe, we connect a transmitter to it and introduce a signal, which we then sync with our locator to trace the pipe and report its depth and direction. In cases where we cannot directly connect to a metal pipe but have an approximate location, we can set the transmitter to induction mode to introduce a signal onto the pipe, which our locators can detect. Locating energized circuits is done by locating the electromagnetic field they generate.

The process begins with a transmitter connected to the underground utility. This device generates an electromagnetic field by sending an electrical signal along the utility line. The signal may be applied directly (via direct connection) or inductively (using induction techniques for utilities that cannot be directly accessed).

As the transmitter emits the electromagnetic signal, it travels along the utility line, creating a field around it. This signal can penetrate soil and other materials, making it detectable by receiving instruments.

A handheld receiver is used to detect the electromagnetic field generated by the transmitter. The operator moves the receiver across the ground surface above the suspected location of the utility.  The receiver is tuned to recognize specific frequencies emitted by the transmitter, enabling accurate identification of the utility's location.

As the receiver approaches the utility, it communicates signals to the operator through visual aids (such as lights or screen displays) and audio cues (beeps or tones). The strength of the received signal varies based on proximity to the utility, indicating its depth and location.

The technician analyzes the readings from the receiver to map the utility's path and determine its position relative to the surface. This information is essential for identifying the utility's depth and ensuring its accurate location for safe excavation or construction.

It is particularly effective for metallic utilities, such as metal pipes and cables. However, it can also locate some non-metallic utilities by inducing a signal in them.

The effectiveness of EM locating may decrease with greater depths, especially in highly conductive soils or areas with interference.

While EM methods can locate some non-metallic utilities using induction, they are less effective compared to metallic ones. By understanding how electromagnetic locating works, technicians can efficiently and accurately detect buried utilities, enhancing safety and planning during excavation projects.