David Marc Fishman asked:


The main part of metal detectors is the control box, shaft, and search coil. Control box which has speaker, batteries, and microprocessor coordinates all activities. To protect the food source many companies use metal detectors to check for metal contaminates in the food, and some drug companies use the metal detectors to check for the same thing in drugs.

Besides metal detection, a walk-through metal detector includes and interface for an operator and a control unit plus environmental tolerance, electro magnetic compatibility, and the assurance of quality control. The control box is the brain of a metal detector. The magnetized metallic objects under the ground send a signal to the control box. Metal detectors that are used in mining need to be compact because of the space restrictions so the control unit and the search coil are integrated into a single unit.

This disk comes off the shaft at an angle, which allows it to be held parallel to the ground. Hand held detectors come in various types, professional, commercial, all-purpose, gold metal, beach and metal that is a relic. Many people use metal detectors to comb the beach for treasures, people are looking for coins, or any other type of metals that might produce a wealth of income. If you are walking along a beach you might come across many people with their instruments looking for these treasures. Since 911 security has gotten tougher and many airports and schools have turned to metal detectors, as well and government buildings, hand held metal detectors are often an important part of security procedures.

A great method of locating and preventing the use of dangerous items such as handguns or knives is the hand held metal detector. They are hand held security metal detectors and walk through metal detectors. Walk over or hand held models of metal detectors are normally used in airports.

Best rated walk through metal detectors have high target selection, low rate of false alarm, consistent detection, and a two way directional system. Cheap metal detectors are available in hand held, waterproof, and walk through models. Walk through metal detectors offer quick and effective processing.

Underwater metal detectors can cost around $400-$600. Underwater metal detectors are widely used to locate metallic objects under water. Underwater construction companies use underwater metal detectors for pipeline or cable locating functions. Some of the underwater metal detectors can adjust the search depth.

Advanced security metal detectors use low radiation x-rays for screening. Many metal detectors have microprocessor technology to check for coarse grained food in cornflakes, popcorn and noodles. Advanced gold detectors can also resist dust and moisture. Some of the advanced gold metal detectors have three modes for speed tracking.

Usually, the price of a metal detector starts from $65. Some sites offer price discounts.

Most sites provide a price list for metal detectors. The price of metal detectors may vary, based on features and functions. If you are just starting out it is a good idea to purchase an inexpensive model before sinking the dollars into the hobby.

Robert W. Benjamin asked:


Metal Detecting for fun or profit can be one of the most exciting and rewarding of hobbies. A metal detector can cost very little, as low as $50 or higher that $400 for a top of the line model. This is one hobby where you really do get what you pay for, because the more expensive top of the line detectors use the most advanced technology and they have the best features available.

Metal Detectors use one of three types of technology:

BFO (Beat Frequency Oscillation) – Metal Detectors using BFO technology have two coils of wire, one large coil is located in the search coil of the detector, the other small coil of wire is located within the System Control Pack. Each coil of wire is connected to an oscillator that produces pulses of current. These pulses of current pass through the coils generating radio waves. A receiver housed within the System Control Pack receives the radio waves and makes a series of tones based upon the frequencies of the radio waves. When the detector search coil passes over a coin or other metal item a magnetic field is created around the coin or metal item, this magnetic field causes interference with the frequency of the radio waves generated by the search coil. And changes the tone produced by the reciever.Metal Detectors using BFO technology are the ones your likely to get when paying under $100 for, that’s right, the cheapies. The BFO technology is the easiest and cheapest to make, thus the prices of the detectors are cheap. The only problem is, BFO technology is very limited when compared to PI and BFO detectors, and the ability to distinguish between junk metals and silver or other coins is very poor.

PI (Pulse Induction) – Metal Detectors using PI technology sometimes use a single coil or a series of coils working together as a transmitter and receiver. Short bursts of electrical current are send through a coil of wire, causing a magnetic field. When the burst of electrical current ends the magnetic field reverses polarity. A sharp electrical spike is created, then more pulses are created, the whole process repeats and works like a series of echoes, giving a different report or echo depending upon the metal it encounters. This type of metal detector is not very good for discrimination between different types of metals or coins, but it is good to use where some other types of metal detectors have trouble working, such as in salt-water, and metals can be detected much deeper with this technology than the others.

VLF (Very Low Frequency) – Metal Detectors using this technology have two search coils. One coil called the ‘transmitter coil’ transmits electricity rapidly many times per second, first in one direction around the coil, then in the other direction. The other coil called the ‘Receiver Coil’ acts just like the name implies it receives frequencies or data that come or ‘bounce’ back from the objects the transmitter coil detects in the search area. This type of Metal Detector is great for it’s ability for being able to distinguish between different types of metals.

The first metal detector my wife and I bought together cost about $69.00 it was one of them cheap ones that used the ‘BFO’ technology. This was one of them metal detectors you see in the magazines that sell other household items, etc. You can buy cheap metal detectors like these at most Radio Shack stores, and some K Marts and Wal Marts. The first day we took the metal detector outside we started finding some neet things and my wife and I were hooked. We did find our share of junk items in the yard, like aluminum foil, nails and the usual pull tabs and junk metal. But we also found 7 old diecast cars in great condition. They were all different and were ‘TOOTSIE’ diecast vehicles. I looked on eBay and the bunch was worth around $15 or more. We also found a 1961 silver Roosevelt dime in fine condition, in our yard, plus the usual pennies.

After reading about how the 3 different types of Metal Detector technologies work and differ from each other, you must decide how or what you will be mostly using your metal detector for. Will you be hunting for small objects like coins, jewelry and gold nuggets, or searching for a large cache or object. The things you may want to use your detector for, play one of the most important factors besides pricing in deciding what type of detector to buy. Most folks want a detector that is great at finding coins, gold nuggets, and jewelry on the land and in small creeks and streams, this would be a detector using ‘VLF’ technology. Almost all of the modern detectors have a waterproof search coil which make searching in shallow creeks and streams possible.

There is Computer Software that is made just for the hobby of Metal Detecting. The software is called: Metal Detector – Treasure Hunter Professional, and may be seen at this website address:

http://www.rb59.com/md/meal.html

By Robert W. Benjamin

Copyright © 2006

You may publish this article in your ezine, newsletter on your web site as long as it is reprinted in its entirety and without modification except for formatting needs or grammar corrections.

MIKE SELVON asked:


Metal detectors are quite useful. They have many uses in many different fields, some of which include: the military in mine fields, airports and other security checkpoints, geophysical prospectors, and beach-combers.

The metal detector is also included in the detector radar family, because many use radar in their systems. Other members of the detector radar family include: car radar detector systems, weather radar systems, and cordless radar systems.

Metal detectors are made up of an oscillator that produces an alternating current that passes through a coil, which creates an alternating magnetic field. This means that when an electronically conductive metal is near the detector, it creates eddies of air, which causes a change in the magnetic field, which enables the operator to see where the metal is.

Handheld detectors are the most common, and are used in the majority of cases. Even land mines can be detected through the use of handheld devices. However, for really deep metals, ground penetrating radar is used in conjunction with the metal detector to unearth the hidden metal.

The metal detector has an interesting history. The first metal detectors were created in the late 19th century. The original inventors of the idea hoped to be able to create easier methods of finding ore for miners. One physicist, Heinrich Wilhelm Dove, invented the induction balance system in those days, but it took a hundred years for others to see the need for his idea.

Early machines were difficult to use, and took a lot of battery power. In the 1930′s, the modern metal detector format began to emerge. Gerhard Fisher is the first patented inventor of the metal detector. He discovered metal detecting quite by accident, when he found a discrepancy in his radio navigational methods. His model was used in WWII, yet afterwards, when there were surplus detectors lying around, the hobby of finding metal for entertainment was formed.

A metal detector is a very useful and entertaining tool. It is hard to imagine someone never having seen one. Nearly everyone has come in contact with metal detectors at least once. It is an interesting fact that the metal detector is part of the detector radar family.

This is due to the fact that many detectors use a cordless radar system in their mechanisms. The metal detector also has an interesting history, and thinking about it the next time you’re standing at a security checkpoint will give you something to ponder to pass the time.