Asking the question, how deep does a metal detector go is like asking how long is a piece of string?
There are many factors that will contribute to the depth capability of your metal detector.
If I was to answer it as simply as possible, without taking into consideration the numerous factors, giving an average, approximate answer, I would say a metal detector can achieve depths of between 8 and 12 inches.
Though, as I have said many factors will contribute to you achieving greater depths.
Lets take a closer look at some of the factors that play a part in how deep your metal detector goes.
Contributing metal detector depth factors
Ground conditions
So the condition of the ground plays a huge factor in determining how deep your metal detector will pick up targets.
Generally speaking if the ground is wet, your metal detector will be able to pick up items buried deeper. This is because the water in the ground helps by increasing conductivity.
Really dry ground isn’t the greatest to achieve good depths, this doesn’t mean your detector wont work though because it will.
I have always had the best days metal detecting a day after a good downpour of rain.
Your detector
The brand and model of your metal detector will also play a large part in determining how deep your metal detector will be able to pick up targets.
More advanced metal detectors manufactured by the leading brands such as Garrett, Minelab, XP, Bounty Hunter, Teknetics, Nokta etc will be able to achieve more depth.
This is because these metal detectors will have been tweaked, tested and optimised to achieve this.
Size of the object in the ground
Naturally the larger the target the easier it will be to pick up by your metal detector, especially if your item is at considerable depth.
I’ve had some majorly deep larger metal targets.
How the object lays in the ground
Sounds silly right? However the orientation or angle of which the object is buried in the ground will also contribute to if your metal detector will pick it up at depth.
Even more shallow items that are laid at the wrong angle can be hard to detect for your metal detector.
I believe it would be to do with the surface area, so a coin laid flat has a larger surface area than a coin that is on it’s side and thus will be easier for a detector to get a signal back from.
So if its laid flat it’s likely you will pick it up deeper than if it were on its side.
What metal the object is made of
Some metals have much better conductivity so therefore can be detected at deeper depths by your detector.
Metals like silver have a high conductivity so its likely your detector will pick these items up when they are deeper than usual, other metals include copper, brass, bronze, gold.
Frequency of the metal detector
Lower frequency metal detectors, or setting your detector to a lower frequency if you’re lucky enough to have multi-frequency selection will help you achieve greater depths.
This is because low frequencies have long waves that penetrate the ground more simply than high frequency detectors.
The coil
The larger the coil the deeper the metal detector will go generally speaking. It’s not always the case though and of course brand and model of the coil will play a part.
Larger coil upgrades for your machine will help you achieve more depth, especially if your machines in beginner ranges such as the Garrett Ace series. It’s very popular for users to upgrade to a Nel Tornado coil to achieve greater depths when out metal detecting.
Ground mineralization
A large determining factor when trying to get as deep as possible with a metal detector is the composition of the ground or ground mineralization.
Most metal detectors that are manufactured now come with a built in feature that will “auto ground balance” what this means is the metal detector will tweak its settings to function at maximum performance after taking a look at the mineralisation of the ground.
Taking into account the ground conditions will help your detector reach maximum depths, it will also stop you from getting “ghost” or false signals.
Pulse Indication Metal Detectors
It’s a well known fact in the detecting world that Pulse induction metal detectors will be able to achieve better depths than a VLF detector.
Some examples of pulse induction metal detectors include the Minelab GPX and the Garrett ATX.
The only issue with these machines is that they go very deep and can pick up unwanted targets at great depths due to the lack of discrimination in comparison to VLF metal detectors.
When I say deep we are talking a couple of feet at times!
Ultimately you’re going to find yourself digging very large holes and sometimes recovering a rusty nail.
You can read more about how a pulse induction machine works here.
Summary
So to summarise, how deep a metal detector will go highly depends on all of the above contributing factors and probably more that I haven’t mentioned.
On a normal day, in usual conditions you can expect to achieve depths of between 4 and 8 inches down.
To achieve maximum depths with your metal detector take a look if coil upgrades are available, go metal detecting after it’s rained, set your ground balance and ensure you have a good metal detector!
