Finding treasure is very exciting, because who does not love finding valuable items? You probably love your metal detecting hobby and finding some great items, but have you ever wondered how does a metal detector work?
Millions of people around the world enjoy metal detecting and the great moments of uncovering treasures. metal detectors use the same technology as military and security services.
Of course, the professionals use them to uncover mines, guns, and knives, and us, regular detectorists get more excited about gold rings and nuggets. Let’s talk about the technology behind metal detectors and how does a metal detector work.
When Magnetism Met Electricity
If you ever made an electromagnet by wrapping a coil of wire around a nail and hooked it to a battery, you probably know that magnetism and electricity are like an old married couple. Where you find one, you will find the other nearby too.
Over the decades we put this idea to good practice, like just simply look around you. Electric appliances, laptops, lamps and more. The electricity we use comes from power plants and its made by a generator, which is really just a big drum of copper wire.
In short, you can use electricity to make magnetism, and magnetism to make electricity. James Clerk Maxwell summed all this up in the 1860s and he developed Maxwell’s equations. Maxwell said that electricity and magnetism are two parts of the really same thing: electromagnetism. And that sums up how does a metal detector work.
How Electromagnetism Powers A Metal Detector
Of course, different metal detectors work in different ways. but there is simple science behind all of them. A metal detector contains a coil of wire, which is known as the transmitter coil. When electricity flows through the coil, there will be a magnetic field around it too.
As you sweep the detector on the ground you make the magnetic field move to. Maxwell also said that if the electricity moves into a piece of metal, such as your target, it will also create some magnetism as well. When you move your metal detector around a piece of metal, the two components will attract each other.
The metal detector will pick up on this second magnetic field. There is a second coil of wire, called the receiver coil which is connected to a loudspeaker which will notify you of targets.
As you move the detector around the piece of metal, the magnetic field produced by the metal gets through the search coil. This way the electricity will flow through it. You move the detector over the metal, electricity gets to the receiver coil, and it will make the speakers beep.
The closer the target is, the stronger the magnetic field will be, thus the louder and louder beeps. This is the basis of how does a metal detector work.
How Deep Will A Metal Detector Detect?
There is no exact answer to this because all metal detectors are different. If you are a newbie, these are the best beginner metal detectors on the market with great depth indicators.
Size, shape, and the type of metal are big factors in detecting. The bigger the object the easier it is to find it. Objects buried flat are easier to find because they create a bigger target area.
Oxidized or corroded items are harder to find. The soil is also a big factor in detecting. Generally speaking, the average metal detectors work at a maximum depth of 8-20 inches.
Can Metal Detectors Tell The Difference Between Metals?
They most certainly do. Metal detectors, even the beginner and not so expensive types can tell the difference between metals. There are usually target IDs on metal detectors to help you identify objects.
What Kind Of Metal Sets Off Metal Detectors?
All types of metals set off metal detectors, but the most common is iron. This is why many metal detectors have an iron filter mode because iron mostly means junk like coke cans, old tin cans, tinfoil and other types of trash. Zink, gold, copper, aluminum, bronze, silver, and other metals can set off metal detectors, and most often you can set your preference.
What Metals Cannot Be Detected By A Metal Detector?
Metal detectors work with metals, so they will detect every type of metal. Metal detectors have a little bit of trouble with stainless steel, as it has low magnetic permeability. Metal detectors work best with ferrous metals.
Do Metal Detectors Work On Gold?
Yes! Gold is the most beloved treasure by most metal detectorists. Metal detectors easily pick up on gold signals, especially if you have one of the best metal detectors for gold.
Who Invented Metal Detectors?
Metal detectors date back to around 1881 when US President James A. Garfield was shot. One of the bullets could not be found in the President’s body telephone pioneer Alexander Graham Bell cobbled together an electromagnetic metal-locating device based on Heinrich Wilhelm Dove’s model.
The bullet was not found, but Bell’s device worked well. Many people credit this as the very first electromagnetic metal locator. Bell was on a good way to know how does a metal detector work.
Portable metal detectors were invented Gerhard Fischer who founded the Fisher Research Laboratory in 1933. Fisher remains the leading metal detector manufacturer to this day. The first computerized metal detector was founded by a NASA employee, D. Charles L. Garrett in 1987. These men really figured out how does a metal detector work.