Ground Penetrating Radar vs. Metal Detector for Oil Tanks
People often ask which tool is better for finding a buried oil tank. The honest answer is that they answer slightly different questions, and the best result usually comes from using both.
Metal detectors and electromagnetic locators
These respond to metal. A steel tank is a large mass of metal, so it produces a strong response. They are quick to use over a whole yard and good at telling you where metal is.
Strengths: fast coverage, strong response to steel. Limits: they do not tell you what the metal is. A tank, a buried pipe, rebar, a fence footing or a car part can all respond. Tanks made of fiberglass or other non-metal material will not show.
Ground penetrating radar
Radar sends signals into the ground and records the echoes that bounce back from objects and changes in the soil. The result is a cross-section picture. A trained operator reads shapes in the picture to tell whether something looks like a tank.
Strengths: it can show objects that are not metal, and it shows shape and depth. Limits: results depend on soil. Wet clay and other conductive soils reduce how deep the radar can see. It is slower than a metal detector, and it needs a reasonably clear surface to move on.
Why use both
A metal detector quickly flags where to look. Radar then shows what the object looks like. Where the two agree, confidence goes up. Where they disagree, you know to look closer.
What neither can do
Neither method guarantees that every tank will be found. Buried utilities, reinforced concrete, structures and vegetation can limit coverage. We discuss this in Can an Oil Tank Sweep Miss a Tank?.
Which should you ask for
Ask the company which methods it uses on your type of lot, and why. A good company explains its choice instead of selling one tool. See How to Choose an Oil Tank Sweep Company in NJ.
You can read about our radar work on our ground penetrating radar page and our oil tank sweep page. Call 732-673-1584 with questions.
