Electromagnetic Induction in cable and pipe location
Electromagnetic induction is a technique for locating underground services (pipes, cables, sewers) that is used across the industry. It can be used to search a large surface area relatively quickly and can be used to measure depth as well as trace and identify a line without breaking ground.
The scientific basics of Electromagnetic induction
Electromagnetic induction was discovered in the early 1800s by Michael Faraday and can be found in most pieces of technology today from mag stripes to induction cooktops to electric motors.
The fundamental principles of electromagnetic induction are:
- Electric currents produce a magnetic field around (this is called electromagnetism).
- Alternating currents have magnetic fields that fluctuate.
- When a conductor is placed between fluctuating magnetic fields, it will produce an electrical current that will flow through the conductor.
In most other applications of electromagnetic induction, the end goal is to create and electrical current to power something but in utility location we use it create a current that we can detect.
Why Electromagnetic induction is important utility location
Amateur locators may make the mistake of doing a passive sweep for underground utilities. The problem with this is that it won’t detect any cables or pipes that don’t have an active electric current at the time of the sweep because no current = no electromagnetic field. For example, a power line connected to streetlights that are off during the day would not be detected. Nor would anything that doesn’t carry a current in the first place.
This is where electromagnetic induction comes in. Electromagnetic induction can be used to produce a current on any pipes or cabling made from a conductive material, which can then be detected by the locator. This is what we refer to as active location.
How exactly does EM induction and active location work?
EM induction locator devices create a magnetic field, which passes through the ground. When this field moves across any conductive material that runs parallel to it (e.g. a pipe or cable), it will produce a current which can then be detected by the device’s receiver.
A locator who is expertly trained in the use of EM induction can sweep your project site to:
- locate buries pipes and cables,
- trace and identify specific lines,
- estimate the below ground depth of the services,
- and sometimes even find cable faults.
Electroscan – experts in EMI
Electroscan’s team of location and detection specialists are thoroughly trained in the use of Electromagnetic induction location technology. They know when and how to use it correctly and can help you get a more complete picture of what lies below the surface of your worksite or project area.
Our team combines EMI with the various other technologies at their disposal to methodically detect and locate the underground assets and utilities you need to be aware of before you commence work.
Electroscan offers utility detection, location and mapping services across Queensland to support all of your subsurface utility engineering needs. Electroscan’s highly skilled team of detection and location specialists use a comprehensive range of innovative technologies and surveying techniques to deliver certainty and help manage risks for your projects.