Metal detecting is a very fun and exciting hobby. If you are lucky, the hobby can be lucrative too. This is because, in addition to detecting coins, the right metal detector can help detect buried gold. You must, however, remember that finding gold using a metal detector is not easy. All in all, for hobbyists, finding valuable items such as gold and silver coins will just be a plus. But how exactly does a metal detector work?
Brief History
Alexander Graham Bell is believed to be the inventor of the metal detector. When President James A. Garfield was shot and the medical team could not locate the bullet, Graham assembled a device in a hurry based on the ‘induction balance’ principles that had been pioneered by Heinrich Wilhelm Dove, a German physicist. While the device did not save the president’s life, it helped locate the bullet.
Modern-day metal detectors are far more complicated than what Alexander Graham Bell built on that day. To better understand how the device works, it is important to start with anatomy.
Anatomy of the Metal Detector
To understand how the metal detector works you have first to get familiar with the key components. While metal detectors don’t look the same, they use the same principles to work. As a result of this, most of their parts are similar. Here are the four components you need to familiarize yourself with.
1. Shaft
The shaft is the centrepiece of the whole device. All the components are attached to it. In many devices, the shaft is adjustable so that you can comfortably use the device based on your height.
2. Stabilizer
The purpose of this attachment is to make it more comfortable to use the metal detector. It is responsible for stabilizing the metal detector when you are in motion.
3. Control Box
This is what contains the power and brains of the metal detector. It consists of the microprocessor, battery, readout, device controls and speakers.
4. Antenna
This is the bottom part of the metal detector. It is mostly elliptical or round in shape. You may hear it being referred to as the search head, loop or search coil. It has coils which are needed for the metal detector to work.
How It Really Works
When it is turned on, the metal detector will transmit a magnetic field and use that field to analyze the target area. The antenna serves the purpose of a transmitter. It is what generates the magnetic field that is created by electricity running through the coil. The magnetic field that is generated causes electricity to flow through a buried metal object when it gets in the field.
The antenna has a second coil which acts as the receiver. The purpose of the receiver coil is to detect any changes in the transmitted magnetic field. There is a change to the transmitted magnetic field when a stricken metal object absorbs it. The receiver checks for alternating voltages caused by absorbed energy. When a metallic object causes an alteration in the magnetic field, the received magnetic field is weaker than the one that was sent out.
The information received by the receiver is then relayed to the metal detector’s control box through a cable. The weaker returning magnetic field is amplified before being sent to the speaker with a distinct audio tone. Some metal detectors may have a display with a needle indicator which senses the change in the magnetic field.
It takes time to understand what a distinct tone or needle movement means. Over time you will be able to understand what exactly is buried without having to dig up everything the metal detector detects. Some modern metal detectors have advanced technology that makes it easy to distinguish certain metals.
Metal Detecting Technology
When shopping for a metal detector, it is good to remember that there are two main types of metal sensing technologies: Very Low Frequency (VLF) and Pulse Induction.
VLF is the most affordable type of metal detector technology out there. It has two coils that work together to detect metals. The technology is popular with treasure hunters because it makes it easy to distinguish different metal types. Metal detectors that use this technology are more sensitive and very accurate. The VLF technology is also ideal when detecting precious metal such as gold and other metal objects with a low metal pulse.
Pulse Induction, on the other hand, is a newer technology. It is common in security metal detectors. The unique thing about pulse induction metal detectors is that they can detect metal that is deeper underground. Most of these detectors only use a single coil. While devices that rely on Pulse Induction are effective in detecting buried metal, they make it hard to distinguish between the different kinds of metals. They are also more expensive. When treasure hunting, using pulse induction metal detectors only makes sense when you are searching in an area with a high mineral presence.
Why Coil Size and Frequency are Important
The important point to remember when shopping for a metal detector is that the bigger the coil is the further the depth the detector will be able to detect. The drawback, however, is that coils that allow for deeper metal sensing will not be as accurate.
Low frequencies penetrate deeper into the ground but have very little sensitivity to small items. High-frequency detectors, in contrast, are great for finding small items but will not penetrate deeper into the ground. Your choice will depend on what you are searching for. The majority of metal detectors used to search for gold use a higher frequency.
Whether you plan on searching for precious metals on the beaches, historic sites, and parks or on old shipwrecks, the above information will certainly help you find the best metal detector for the job. The best thing is there is a metal detector today for virtually any purpose. Some even come with adjustable frequencies. Your choice will also be influenced by your budget. The best metal detectors are more expensive.