Metal and Gold New Plus TechnologyAlexander Graham Bell invented the first crude metal detector in 1881In 1881, Alexander Graham Bell invented the first metal detector. As President James Garfield lay dying of an assassin's bullet, Alexander Graham Bell hurriedly invented a crude metal detector in an unsuccessful attempt to locate the fatal slug. Bell's metal detector was an electromagnetic device he called the induction balance. Gerhard Fischar - Portable Metal DetectorIn 1925, Gerhard Fischar invented a portable metal detector. Fischar's model was first sold commercially in 1931 and Gerhard Fischar was behind the first large-scale production of metal detectors. According to the experts at A&S Company: "In the late 1920's, Dr.Gerhard Fisher, the founder of Fisher Research Laboratory was commissioned as a research engineer with the Federal Telegraph Co. and Western Air Express to develop airborne direction finding equipment. He was awarded some of the first patents issued in the field of airborne direction finding by means of radio. In the course of his work, he encountered some strange errors and once he solved these problems, he had the foresight to apply the solution to a completely unrelated field, that of metal and mineral detection.
The Future Series Detectors are extreme treasure hunting metal detectors , ground penetrating radar and Magnetometer. Not only do they see metal in the ground like metal detectorsbut also see disturbances in the soil where non-metallic utilities like PVC and HDPE pipes may have been buried. GPR (Geophysical PhaseReader) with 3D Imaging software that determines approximate size and location. Ground penetrating radar is cumbersome and slow whereas the future gpr is quick and efficient gpr, radar, metal detectors, detector, detecting, treasure hunting, archaeology, detection,geotechnical, mining, prospecting, cable locator, pipe locator, geophysical, buried cable utility locator, georadar, unexplodedordnances, forensic, radar support, ground radar image mapping, rebar, sub-surface, OKM, underground detecting, bodenradar, ortungstechnik,bedrock mapping, environmental, Metal detector, Localizer 3000, Future 2005, Rover C, Walkabout deluxe, i-160, Geoseeker, Waterfinder, Gralfinder, OKM Ortungstechnik GmbH, Cavefinder, Schatzsuche, Goldgun, GEMS, exp 4000, exp 5000.
Metal Detecting is an excellent hobby and pastime for the whole family. This website is here to help you select the right detector based on the experience of other pWhat types of metal detectors are there?There are many different detectors, some are more complicated then others. The basic ones are easy to get used to, with less features and buttons. Turn it on and off you go! You can't get around practice though, and the more complicated the detector, the more practice you will need. Which is the best detector? What is the best gold detector? Read some of the user reviews to find out.Recommended Beginner DetectorsLand or relic detectors are used mainly on land or in the woods, playgrounds, parks, etc. They can be used at the water edge and even in the water a couple of inches, most coils are waterproof, but don't drop your whole detector in the water. If you're just starting out in the hobby, here are the most popular and affordable beginner metal detectors. The Rover C, exp 4000 , exp 5000 and the Localizer 3000 Of course there are many more models of detectors to choose from, but these will get you started on the right track.Waterproof DetectorsMaybe you're close to the ocean or lakes, and are thinking of jumping in the water with your metal detector to find out what was lost there? If finding jewelry is your thing then a waterproof detector is a must. eople like you.
Gold Detector and Metal DetectorGold Detector and Metal DetectorMetal detectors use electromagnetic induction to detect metal. Uses include de-mining (the detection of land mines), the detection of weapons such as knives and guns, especially at airports, geophysical prospecting, archaeology and treasure hunting. Metal detectors are also used to detect foreign bodies in food, and in the construction industry to detect steel reinforcing bars in concrete and pipes and wires buried in walls and floors.In its simplest form, a metal detector consists of an oscillator producing an alternating current that passes through a coil producing an alternating magnetic field. If a piece of metal, which is electrically conductive, is close to the coil eddy currents will be induced in the metal, and this produces an alternating magnetic field of its own. If another coil is used to measure the magnetic field (acting as a magnetometer) the change in the magnetic field due to the metallic object can be detected.The first detectorsMetal detectors have been around for much longer than most people realize. Towards the end of the 19th century, many scientists and engineers used their growing knowledge of electrical theory in an attempt to devise a machine which would pinpoint metal. The use of such a device to find ore-bearing rocks would give a huge advantage to any miner who employed it. The German physicist Heinrich Wilhelm Dove invented the induction balance system, which was incorporated into metal detectors a hundred years later. Early machines were crude and used a lot of battery power, and worked only to a very limited degree. The Scottish physicist, Alexander Graham Bell, attempted used such a device to attempt to locate a bullet lodged in the chest of American President James Garfield in 1881, though the attempt was unsuccessful because the metal bed Garfield was lying on confused the detector. 
Modern developmentsThe modern development of the metal detector began in the 1930's. Gerhard Fischer had developed a system of radio direction-finding, which was to be used for accurate navigation. The system worked extremely well, but Dr Fischer noticed that there were anomalies in areas where the terrain contained ore-bearing rocks. He reasoned that if a radio beam could be distorted by metal, then it should be possible to design a machine which would detect metal, using a search coil resonating at a radio frequency. In 1937, he applied for, and was granted, the first patent for a metal detector. His designs were soon put to the test in a practical way, as they were used as mine detectors during the Second World War. They were heavy, ran on vacuum tubes, and needed separate battery packs - but they worked. After the war, there were plenty of surplus mine detectors on the market; they were bought up by relic hunters who used them for fun and for profit. The hobby of metal detecting had been bornFurther refinementsMany manufacturers of these new devices brought their own ideas to the market. Whites Electronics of California began in the 50's by building a machine called the Oremaster Geiger Counter. Another leader in detector technology was Charles Garrett, who pioneered the BFO (Beat Frequency Oscillator) machine. With the invention and development of the transistor in the 50's and 60's, metal detector manufacturers and designers made smaller lighter machines with improved circuitry, running on small battery packs. The metal detector was reduced to a size that even a child could use - and use them they did. Fabulous finds were made; prehistoric gold ornaments, chests of Roman coins, jewelled daggers, arrow heads- all types of metal artifacts were coming out of the ground. Suddenly, there was a huge requirement for those early electronic magic wands which might make a man rich overnight. Companies sprang up all over the USA and Britain who wished to supply the growing demand.
DiscriminatorsTechnological changes were taking place at a rapid rate too, and very few of the smaller companies managed to stay in competition with the big outfits. GOLDAK, METROTECH, IGWT, TEC, and, quite recently, ARADO ceased production of hobby machines. Some devotees of metal detecting still treasure their Arado machines, which had a reputation for being difficult to set up, but were reputed to be the deepest-seeking hobby detectors ever made. The biggest technical change in detectors was the development of the induction-balance system, where two coils are set up in an electrical equilibrium to produce a 'null' or zero balance. Introducing metal to the vicinity of the coils caused them to unbalance, producing a change of tone in the machine's speaker. Scientists had long known that every metal has a specific response to stimulation by alternating current. Each metal produces a time lag or 'phase angle' in its induced current, in relation to the drive current. This meant that detectors could now be set up to ignore unwanted phase angles, and respond positively only to desired metals. But there was also a downside to the development of the 'discriminator' detectors. Introducing discrimination always had the effect of reducing the sensitivity of the machine, so it was less able to find deep objects. In addition, there was the fact that some desirable metals were quite near the area of unwanted metals, such as iron. Gold, particularly in alloy form, was quite close to tinfoil in the overall spectrum, so the discrimination control had to be used carefully. The price to be paid for setting up a detector to ignore iron and tinfoil was the possibility that, sooner or later, the user would scan over, and ignore, a valuable find - perhaps a diamond engagement ring on a beach.New coil designsCoil designers also tried out innovative designs. The original Induction Balance coil system consisted of two identical coils placed on top of one another. Compass Electronics produced a new design; the two coils were made in a D shape, and were mounted back-to-back to form a circle. This system was widely used in the 1970s, and both concentric and D type (or Widescan as they became known) had their fans. Another development was the invention of detectors which could cancel out the effect of mineralization in the ground. This gave greater depth, but was a non-discriminate mode. It worked best at lower frequencies than those used before, and frequencies of 3 to 20 kHz were found to produce the best results. Many detectors in the 1970s had a switch which enabled the user to switch between the discriminate mode and the non-discriminate mode. Later developments switched electronically between both modes. The development of the Induction Balance detector would ultimately result in the Motion detector, which constantly checked and balanced the background mineralization.Pulse inductionA pulse induction metal detector with an array of coilsAt the same time, developers were looking at using a completely different type of technology in metal detectors. This was the process known as Pulse Induction. Unlike the Beat Frequency Oscillator or the Induction Balance machines which both used a uniform alternating current at a low radio frequency, the pulse induction machine simply fired a high-voltage pulse of signal into the ground. In the absence of metal, the 'spike' decayed at a uniform rate, and the time it took to fall to zero volts could be accurately measured. However, if metal was present when the machine fired, a small current would flow in the metal, and the time for the voltage to drop to zero would be increased. These time differences were minute, but the improvement in electronics made it possible to measure them accurately and identify the presence of metal at a reasonable distance. These new machines had one major advantage: they were completely impervious to the effects of mineralization, and rings and other jewelery could now be located even under highly-mineralized 'black sand'. They had one major disadvantage too: there was no way to incorporate discrimination into a Pulse induction detector. At least, that was the perceived wisdom of scientists and engineers until Eric Foster, who had run Location Technology in Ireland for many years, started a new company in Britain and produced the Goldscan, the first Pulse Induction detector which had the apparent ability to differentiate between metals. This was a new type of 'junk eliminator' circuit, which relied on the size of the target as well as its metallic response to give a control that would show positive for a gold ring and negative for a copper coin. Its ability to differentiate between non-ferrous metals was not an exact science, but gave unparalleled depth on mineralized soil or sand. Pulse Induction detectors are now widely used in the construction industry; the Whites PI-150 is an industrial machine which can detect large objects to 10 feet, using a 12 or 15 inch coil.Future detectorsModern top models are fully computerized, using microchip technology to allow the user to set sensitivity, discrimination, track speed, threshold volume, notch filters, etc, and hold these parameters in memory for future use. Compared to just a decade ago, detectors are lighter, deeper-seeking, use less battery power, and discriminate better.New genres of metal detector have made their appearance. BB (Beat Balance) and CCO (Coil Coupled Operation) were unveiled by the electronics press in 2004. Both were invented by electronics writer and designer Thomas Scarborough and combine unprecedented simplicity with good sensitivity.Metal detectors in archeologyIn England and Wales metal detecting is legal provided permission is granted by the landowner, and the area is not a Scheduled Ancient Monument or covered by elements of the Countryside Stewardship Scheme. Voluntary reporting of finds to the Portable Antiquities Scheme or the UK Detector Finds Database is encouraged. These schemes have their critics, however, including some archaeologists and metal detectorists. The situation in Scotland is very different. Under the Scots law principle of bona vacantia the Crown has claim over any object of any material where the original owner cannot be traced. There is also no 300 year limit to Scottish finds. Any artifact found, whether by metal detector survey or from an archaeological excavation, must be reported to the Crown through the Treasure Trove Advisory Panel at the National Museums of Scotland. The Panel then determines what will happen to the artifacts. Reporting is not voluntary, and failure to report the discovery of historic artifacts is a criminal offense in Scotland.Archeology is beginning to recognize the contribution responsible metal detecting provides in adding to the knowledge of our past. One example is utilizing the skilled use of the metal detector to examine wide areas such as battlefield sites where surface scatters of metal objects may be all that survives. This has recently been demonstrated during archaeological work conducted at Antietam National Battlefield in the United States.
