What’s the Difference Between Electromagnetic and Ferromagnetic Detection?

When you bring out a GPR service to look for undocumented tanks, buried metals, or other not-so-fun surprises buried in your backyard, you want to make sure you are using the right tools for the job. However, each technique has specific uses that dictate which situations you can best utilize them. By knowing the difference between how each technique works and what kinds of objects each can pick up buried in your yard, you can get a fuller picture of what goes on beneath the surface.

Electromagnetic (EM) Detection

By definition, electromagnetic (EM) detection measures the electromagnetic waves that reflect off of conductive metallic materials. These EM waves form when electric and magnetic fields come into contact and travel through anything without a medium. You can read the EM fields given off by buried metallic materials on your property with specially designed ground-penetrating radar.

EM detection makes the most sense when you are trying to detect buried power lines and telephone utilities. The natural EM signals given off by these will register on the EM GPR, and with enough points of contact, you can determine where exactly in your yard the lines fall. 

Ferromagnetic (FM) Detection

The most significant difference between ferromagnetic (FM) and EM detection stems from what the FM detectors pick up. FM waves deal primarily with the magnetic fields that derive from iron-based metals. These metals retain their magnetism even when the magnetic field is removed, making it possible for GPR to detect the objects. Our team utilizes FM detection to scan your property for buried rebar, stakes, and other unattached metals left behind by the previous owners. Additionally, FM detectors are vital during vacuum excavation to keep track of metal casings and utilities that may get in the way. 

Knowing when to use EM and FM detection can make your property buying process go smoother than expected. With GPR One Call, we have the services and experience to ensure that there aren’t any buried surprises on your property that can make renovations or a later sale tricky. Contact our team to schedule your next appointment today!