How to Choose One Metal Detector Technology over Another

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Kid-friendly Metal Detectors

Metal detectors operate by sending magnetic impulses in the ground to detect hidden objects.

The metal which is found can be anything from a worthless metal shard to extremely valuable necklaces, vintage coins, gold or a historic relic. The great thing about metal detectors is you never know what may be discovered.

Every metal detector works the same way using electromagnetism to detect metal which is buried beneath the earth’s surface. They are powered by a battery which creates a portable magnetic so you can survey the ground. When there is metal beneath the surface the detector receives a magnetic charge which works on the same principal of using a small household magnet to pick up a screw. The metal which is below the earth is now magnetized and sends an electronic signal to the detector to inform the operator either visually or by sound. Higher end models will give more details such as depth and the type of metal. The vast majority will sense metal at least a foot underneath the ground. Premium units can explore much deeper.

What Makes Up a Metal Detector?

Every metal detector, no matter the make or model uses the same internal components:

  1. Control box – the box is at the heart of the detector and houses the microprocessor, batteries, speaker, controls and circuitry. In some models it can also have a jack to plug in ear buds or headphones.
  2. Stabilizer – this works as a brace arm which keeps the best metal detector steady while the user sweeps the unit from side to side surveying the ground.
  3. Search coil – is an inductive sensor which detects metal beneath the surface.
  4. Shaft – this joins the inductive sensor search coil and control box. For most models this can be adjusted to fit the operator’s height.

Metal Detector Options

Below we will explore the various options for best metal detectors and why they are used:

PI (Pulse Induction)

These detectors are the favorite for people who hunt for treasure because it can detect metal extremely deep below the ground. It generally utilizes a single coil to detect the metal by putting out a large magnetic field and if metal is detected the signal is reflected directly back to the detector. Another advantage of PI detectors is that they are versatile and the user can switch modes quickly and they can hear the sound of the signal which is reflected immediately to the unit. PI units can distinguish between signals sent from other locations and the signals the unit has sent. Because of this the PI is both more expensive and more accurate than other detectors.

VLF (Very Low Frequency)

This VLF happens to be the most popular detector because it can find various kinds of metals and has a good range. It uses two coils; an inside and outside coil. The inside coil works as a receiver to amplify a magnetic reflection which can be heard in the device. Whereas the outside coil works as an extremely low frequency magnetic transmitter. The transmitter first detects the metal beneath the surface and reflects the magnetic signal.

VLF devices also use electronic circuitry to process the audible signal to the receiver. Essentially the circuit works as a tuner which makes it easy for the operator to only focus on the specific metals they are trying to find. All metals reflect at different ranges, so someone who is looking for treasure has very little use of metals made of steel or aluminum, so they may focus on finding platinum, silver or gold.

BFO (Beat Frequency Oscillation)

These are best suited for beginners to metal detecting because it’s both very low in price and simple to use. BFO detectors have two coils; one to detect the metal with different audio tones and the other coil which oscillates to help create a consistent signal when the frequency is set. The problem with the BFO however, is it is very difficult to distinguish between precious metals and common metals which hold little or no value such as nuts, bolts, screws, nails or cans.

What to Know Before Purchasing

  • Where Do You Want To Search: It matters if you want to primarily search dry land or near or inside a body of water? What is your ultimate purpose in buying the unit? Is it to find valuable jewelry, gold or coins under water? Or do you want to find them on dry land? Even though all metal detectors are somewhat waterproof and can survey water to some extent, but most operate best on dry land. There are specialty units that can go deep underwater. Research the history of the town or state you want to survey to determine if it is likely that there are gold, historic relics, jewelry and valuable coins either above ground or in the water.
  • Duration: How long on average do you want to operate the detector on a weekly or monthly basis? If you are a frequent user it is recommended that you get a unit which has more bells and whistles. Because if you are using the metal detector often you should make it customized as possible to avoid frustration down the road.
  • Price: Buying a basic metal detector won’t set you back that much. But if you can spend a little more it will make your experience both easier and more enjoyable. Also keep in mind there are accessories that you also might want to buy such as a carrying bag, a tool for digging and headphones.