Chad Fox – Page 7 – Treasure Detection – Treasure Hunting for Everyone

Metal detectors are a great way to find old coins, precious metals, and other awesome treasures. The technology that a metal detector uses can sound complicated, but using a metal detector is extremely easy! How Do Metal Detectors Work? Metal detectors transmit an electromagnetic field from the search coil, that penetrates the ground. When the electromagnet field reaches metal, it creates a magnetic field around the object. The receiving coil picks this up and alerts the detector through sound or blinking lights. It is not that complicated at all, despite the science that is involved. Using a metal detector to find treasure is one of my favorite hobbies. You can find old coins, rings, jewelry, and other precious metals. This is just the quick answer to how do metal detectors work, now let's go into the science and history. The Science Behind Metal Detectors The science that is used in metal detectors starts with electromagnetism. This discovery uncovered the relationship between electricity and magnetism. Source. It is used in a metal detector, by transmitting the electromagnetic field through the search coil. This penetrates the metal in the ground, causing a magnetic field to form around the metal object, by energizing it. It is then sent back through the search coil, to the control box, which processes the signal and converts it into a frequency, sound, or blinking light. How do metal detectors work. With the first swipe of the metal detector, the magnetic field is transmitted into the metal object in the ground, where the atoms of that object become energized and magnetic. The second swipe picks up that new magnetic field and sends it back up the search coil to the control box. This is why you must swipe the metal detector back and forth to receive the signal. The History of Metal Detectors The greatest contribution to this technology came from Clerk Maxwell. He developed mathematic equations called “Maxwell’s Equations.” His work helped to figure out that when there is a changing electronic field there is also a changing magnetic field. Source. This is how the concept of electromagnetism was developed. This is one of the main controlling principles of the metal detector. This concept was then used by Alexander Graham Bell, who built an electromagnetic metal finding device for locating the bullet that shot American president James A. Garfield, that was lodged into his arm (the bullet was not found but the technology proved to work.) The portable metal detector was later invented by a German engineer named Gerhard Fischer, who patented his device, called a Metalloscope in 1933. The portable metal detector went through multiple transformations and became the electronic and digital metal detectors that we know today. Metal detectors have been used throughout history, with various uses, during wars, to find buried mines, and to detect guns and other dangerous weapons. They are now a popular way to find lost or buried treasure. Metal Detector Components There are four main components of a metal detector. Each piece serves its purpose in making the device work. Most metal detectors are lightweight and easy to use. The four components of a metal detector: Stabilizer Control Box Shaft Search Coil The four main components of a metal detector. The stabilizer is the piece that connects with your arm, keeping the device steady as you use it. The control box holds the batteries, contains the settings and knobs, and converts the signal into a sound or blinking light. The shaft is the part that the other pieces connect to. The search coil is made up of multiple coils and is the base that you use to sweep across the ground. Types of Metal Detectors There are three main types of portable metal detectors. Each one uses a slightly different technology. You will want to choose the correct type based on your needs. The simpler type (BF0) is not as practical as the more thorough designs. The three types are: VLF (Very Low Frequency) PI (Pulse Induction) BFO (Beat-frequency oscillator) Very low-frequency metal detectors are Induction Balance (IB) detectors that use low frequencies. These metal detectors are built with two coils. The outer coil transmits an alternating current to the metal object in the ground. The inner coil picks up the magnetic field of the conductive metal. Pulse induction metal detectors send a sequence of electronic pulses down to the search coil, producing a magnetic field. The pulse penetrates the ground and locates a target object, which then sends an answering pulse back up to the control box where a circuit measures the pulse. Beat-frequency oscillator metal detectors use two radiofrequency oscillators, that are tuned to a similar frequency. The first oscillator is called the search oscillator, and the second is the reference oscillator. The search coil is disturbed by a conductive metal and the search oscillator shifts to produce a signal. The VLC metal detector has the most range for different types of metal. It is the metal detector used by the more serious treasure seeker. The pulse induction metal detectors can penetrate the ground deeper, allowing you to detect objects deeper down. The beat-frequency metal detectors are one of the first designs ever made. They do not have the accuracy of the other two and are considered outdated. This technology is used in cheap detectors, and toy detectors. Metal Detector Controls There are two main controls of a basic metal detector. These are sensitivity and discrimination. Both of these controls can be adjusted to fine-tune the device to find the metals you are after. You can find the right frequencies by testing the detector on a nail, or penny, and adjusting the frequencies to find the desired object. What is sensitivity on a metal detector? Sensitivity is used to measure the type and size of the metal that you are detecting. The more sensitivity your metal detector has, the more ability it will have to detect small irregularly shaped pieces. What is discrimination on a metal detector? Discrimination is what gives the metal detector the ability to identify targets, based on the type of metal. With this, you can determine if it is worth it, to dig up the metal, based on if it is silver, gold, or a lesser-valued metal. A more complex metal detector may also have a volume nob for the sound and several other elements that are used to fine-tune detection. Each type of metal causes a different frequency and digital metal detectors give you more control over identifying objects. Common digital metal detector elements: SampleIron Nail5 ¢ CoinPull tabAlloy Screw1 ¢ Coin10 ¢ Coin25 ¢ Silver50 ¢ Silver1$ SilverToneLow ToneLow ToneMiddle ToneMiddle ToneMiddle ToneHigh ToneHigh ToneHigh ToneHigh ToneTarget IndicationIron5 ¢P-TABS-CAP1 ¢10 ¢25 ¢50 ¢1$Digital Target Indication0-910-1920-2930-3940-5455-6465-7980-8990-99 Do Metal Detectors Detect All Metals? Some metal detectors can detect all metals, both ferrous and nonferrous. VLF metal detectors are the best for this since they have more versatility. Older models such as beat-frequency oscillators cannot detect all metals. What metals cannot be detected by a metal detector? Metal detectors have a hard time detecting any metal that is not extremely conductive. Stainless steel can be hard to detect because it has poor electrical conductivity. The same goes for other metals with poor conductivity. Metal detectors only detect metal items, they will not detect bones, pearls, gemstones, or other non-metal items. See our article for - Can Metal Detectors Detect Gold. How Well Do Metal Detectors Work? How well a metal detector works is based partially on what type and brand of metal detector you have. Some models have better sensitivity and more options for dialing in the settings. Just like with anything, you get what you pay for. A VLC and BI metal detector works better than the simpler BFO types. No metal detector is 100% accurate, you may have to play with the dials, and swipe over areas multiple times. The best thing you can do is practice with different types of metals. That way you can determine the exact settings for your particular metal detector. Put things like a nail on the ground outside, and then a silver quarter, so you can find out what frequencies are correct for those metal types. This works particularly well for metal detectors that do not have all of the digital settings. Many treasures have been found and reported every year, around the wold. In England, there were over 1,000 treasures discovered in 2018, with many more found in other countries and regions. Treasure finds in England, Wales and Northern Ireland, 1996 to 2018. Source. Do Metal Detectors Work Underwater? Most modern metal detectors are waterproof and can be used partially underwater. This is extremely useful for searching river beds, or beaches. There is a river in Texas called the Guadalupe River, where people go tubing. Friends of mine have found all kinds of rings and jewelry that people have lost in the river, by metal detecting at the points where the water falls down a notch. You may also want to use a snorkel and other water accessories for going underwater to dig in places that the water is deep. You may have to get a particular model if you plan on completely submerging it. Most of them are only waterproof in the bottom half of the metal detector. Frequently Asked Questions Have more questions about how metal detectors work? You might find the answer here in our FAQ. How do metal detectors work?Metal detectors use an electromagnetic signal to detect metal, the target object becomes energized and sends that signal back to the control box and is converted into a sound or blinking light. What are metal detectors used for?Metal detectors are used to find all types of metals, coins, jewelry, lost or buried treasure. They can also be used to find metal markers on your property. The military uses them to sweep for mines. Do metal detectors have radiation?Metal detectors do not have radiation, they use a low-intensity magnetic field to detect target objects such as metal. The same goes for metal detectors that you walk through. How long do metal detectors last?A good metal detector will last for years. Most of them are battery-operated and will work as long as you change out the batteries. Cheap ones may break over time, so you get what you pay for.