Metal detectors are widely used in a variety of applications, from locating treasure to detecting smuggled goods. In the case of metal detectors, the devices typically work by sending an alternating magnetic field through certain conductive materials and recording any electric current generated as an output. This article will take a closer look at how metal detectors operate and why they cannot detect metals in liquid environments such as water or fuel.
How Do Metal Detectors Work in Water?
Metal detectors function by sending an alternating magnetic field through a conductive material, typically via a coil of wire. This alternating magnetic field causes the electrons in the metal to move back and forth in response, creating an electric current that can be detected. Typically, this current is then amplified electronically so that one can measure it. A device called an oscillator is used to generate the alternating magnetic field required to perform this task.
A typical metal detector can send a magnetic field of up to 10,000 Gauss through the coil. To detect items in liquid environments such as water or fuel, one must modulate the strength of the field to match the amount of charge carried by metal in these liquids. This modulation takes place in a crystal oscillator which amplifies and sorts out any current that exists. This oscillator is typically a crystal that changes its shape when it is struck; this movement changes the frequency and amplitude of the magnetic field.
This ability to sense current variation in a magnetic field makes metal detectors one of the best tools in determining solid objects such as gold and gemstones, but there are limitations. Since metals do not respond to changes in magnetic fields, the strength of the electric current must be strong enough to create a detectable change. However, the effect of the magnetic field drops off rapidly as you move away from the coil. For this reason, metal detectors work best when they are held close to the ground.
Why Can’t Metal Detectors Be Used in Water?
The problem with using metal detectors in liquid environments such as water or fuel is that there is no electric charge to be detected. Drawn by the alternating magnetic field, any charge on metal will be offset by an equal amount of positive charge on its opposite side. Though this creates an imbalance in current, one will create no measurable current.
The only exception to this rule would be if an object with a negative charge were present. If that object were of sufficient strength, it could negate the metal’s charge and create a detectable electric current. For example, say an underwater metal detector was set up to search for gold at a depth of one meter. If the metal detector was set up to search for gold at a depth of 10 meters, it could detect a signal at this depth because 10 meters is 1/10 the distance from the device to the target. In other words, any metal that is present in liquid water or fuel will create an electric current capable of detection no matter how small or unnoticeable it is
How Are Submersible Metal Detectors Different?
Metal detectors that are capable of detecting metal underwater can do so by functioning at different frequencies. Setting the frequency of the metal detector coil to match that of the target material can detect its presence regardless of its location or distance from the surface. A metal detector fails to function correctly only in scenarios where electric current exists but cannot be detected.
The development of submersible metal detectors has led to an increase in the use of these devices in search and rescue missions. In the ocean, devices such as the SuperVision Submersible Metal Detector can be used to search for objects and materials that would otherwise be difficult to detect. The same technology is applied in other liquid environments such as landfills, rivers, and lakes. Metal detectors are used by a wide range of people for various purposes, from detecting metal in liquids such as water, fuel, and air to detecting metal objects through solid objects such as walls and fences. These devices have also made it possible to determine the composition of metal objects quickly and easily. This application is currently being developed for both hospitals and nuclear power plants.
Not All Waterproof Metal Detectors Are Made Equally
Before purchasing a metal detector for underwater use, it is essential to determine which device will best suit your needs. Like all electronic devices, there are differences among waterproof metal detectors. The most important aspect of this is determining whether or not the device is submersible. While many waterproof metal detectors are submersible, not all are designed for this purpose. A submersible metal detector requires the ability to withstand pressure within the water, so all of these devices must be water-resistant.
Another thing to consider is how these devices are powered. Some waterproof metal detectors are battery powered, while a vehicle’s power supply powers others. A battery-powered device can draw anywhere from one to ten AA batteries, depending on the model, while the amount of power used will vary widely depending on whether or not it has GPS built-in. A vehicle-powered metal detector requires an adapter that will allow it to plug directly into your car’s cigarette lighter.
Waterproof metal detectors are essential to use when searching for objects through water or other liquid environments. These devices can detect metals that, without them, may not be visible or detectable at all. Among the most crucial waterproof metal detectors is the SuperVision Submersible Metal Detector. This device is one of the best tools you can use in underwater searches, and it can detect even the smallest amount of metal present.