Can Metal Detectors Detect Liquid?

If you have wondered whether or not metal detectors can detect liquids, you are not alone. 

Many individuals who find themselves in the most challenging industrial environments usually lookout for ways to detect liquids. 

Particularly, it would be a great thing since we will be able to tell you if liquids like water exist underneath and then build a well to extract it, yeah?

But do metal detectors come in handy to achieve this?

I did deeper research into this before taking out my metal detector machine for another futile adventure, and here is what I found out:

Sadly, conventional metal detectors can not detect liquids, including water and oil. Such detecting devices are built to signal the proximity of only metals and similar elements/objects that can conduct electricity. 

Examples of this would be detecting cell phones or detecting mini liquor bottles.

Since pure liquid doesn’t conduct electricity, it can not be detected by metal detectors, even when underground.

You might have placed high hopes on the capability of metal detectors, especially considering the rate at which they are being modified with the latest technologies. But it might not be very reassuring to realize that this is just the way it is.

However, there are more interesting factors involving detecting liquids, especially water, using detecting devices.

In the rest of this post, we will beam the focus light on this aspect to establish other ways one can resort to detecting liquids.

Does liquid go off in the metal detector?

Have you ever wondered why it is not advised to use water bottles and other beverages for metal detectors tests? It is simply because these devices produce inaccurate results when it scans water bottles or beverages.

Most of the metal detectors we buy – conventional ones – are not built to be strictly waterproof. So, in essence, only metal detectors that are submersible work well underwater, which means liquid won’t go off when positioned in the area. 

In other words, the way out of liquids being a hindrance to finding precious stones or valued objects is by getting a waterproof metal detector. You should know when and how the device should be used when hunting for treasure around liquids.

Speaking of underwater, liquids such as water go off in metal detectors capable of detecting gold underwater. For example, the glorified Minelab SDC2300 can be submerged up to 10 feet to detect the smallest of gold (even those weighing 1 gram.)

Do metal detectors detect water?

When we establish that normal metal detectors can not detect liquids, we mustn’t blatantly generalize liquids to include their various forms like water, oil, blood. Etc.

Well, metal detectors can’t pick up water, but they are ways to do so using similar devices. In other words, what you need is a machine that can indicate the presence and proximity of water about the area being scanned.

If such a machine exists, as we will see later on, then it is safe to call it a metal detector that detects water. It should not be confused for machines that can operate well on water which we have already touched on earlier on (waterproof detectors)

So, detecting for water using a specified tool/machine/device is known as You dowsing, or as many people call it, water witching.

While there is no scientifical confirmation of the effectiveness of this method, the dowsing practice of detecting water involved using an L-formed aluminum rod and walking around the examined surface to locate possible groundwater.

Aside from that concept, there is no way conventional metal detectors can detect water, just like how it can’t account for liquid in general.

What cannot be detected by a metal detector?

The adventure of a treasure hunter with his metal detector can be futile if the understanding of what his device can detect and what it can’t is not well established. 

As mentioned earlier, Metal detectors derive signals to aid the electrical conductivity of the searched item in the given area. In other words, these devices’ items can detect the need to have a decent electrical conductivity.

Generally speaking, materials like stainless steel are hardly detected by metal detectors because they have very poor electrical conductivity and low magnetic permeability.

The same thing applies to Gemstones and other materials that do not produce signals that are strong enough to be detected by the device. 

These undetectable materials can also make their way past walk-through detectors usually found in highly-secured facilities.

P. S: You can’t “fool” the metal detector by coating detectable materials with non-detectable ones. Without triggering a signal, metals that can never get past metal detectors include gold, silver, copper, and tin.

Meanwhile, MDI Metal Detector Systems can detect all types of metal, including ferrous (magnetic), non-Ferrous (non-magnetic), and stainless steel.

What can pass through a metal detector?

Aside from treasure hunting, Metal detectors can also be integrated as security details. In this context, people usually ask about what can pass through a metal detector. 

These devices play a vital role in ensuring people entering or exiting a particular facility are safe. Walk-through metal detectors are designed to sniff out concealed weapons such as guns or knives, foil-wrapped drugs, and precious metals such as jewelry, precious metals, or antiques.

Generally speaking, metal detectors signal the proximity of iron, nickel, and cobalt either passively or actively. Aside from these metals, others include copper, brass, and aluminum.


From this short article, we have realized that conventional metal detectors can not detect liquids. However, that is not the entire idea encompassing the possibilities of detecting liquids, especially water.

Other machines are tools that can indicate the presence and proximity of liquids or water concerning the environment or surface being scanned only that regular metal detectors can not achieve such.

We have also covered areas of detecting underground water and detecting through the water. If you found this article helpful, feel free to share.

I will continually have a check on the release of newer regular metal detectors in the market and watch out for any groundbreaking innovation, which might be the ability to detect water. Who knows!