Who Invented the Metal Detector? The History of the Metal Detector

who invented the metal detector

Many great minds have improved metal detectors from what it used to be to what we have now. The first inventor that received a patent for metal detectors is Dr. Gerhard R. Fisher. However, there had been the first notion regarding metal detectors and this was through Alexander Graham Bell who is popular for his invention of the telephone.

Metal detectors became more popular during the Second World War when a polish military officer; Lieutenant Jozef Kosacki who was part of the polish resistance based in Scotland used and upgraded metal detectors to help detect land mines. This heavy innovation was sent to EL-Alamein to help clear the land mines laid down by Germans. During the war, the technology was top secret and it remained so after several years.

The Induction Balance

This is the name given to the first metal detector invented. This invention was made by Alexander Graham Bell. In the 1800s. After electricity was invented, several scientists and inventors tried to develop the machine that could locate metals buried underground. It was believed that metal detectors would help with discovering gold buried underground after the “goldrush”, and this would make the inventor very rich.

However, the first metal detector (induction balance) was not made to help find gold, it was to save the life of President James Garfield who was shot on July 2, 1881, at the Baltimore and Potomac Rail Station in Washington. The bullet which did not kill the president was lodged in his back, though he survived the bullet’s impact. It was impossible to discover the precise location of the bullet in the president’s body.

While Alexander G. Bell was visiting the president, he created a metal detector to help find the bullet. Though this was not successful, the president later died from wound infections on September 19, 1881. It was later discovered that the iron bed President Garfield was lying on disrupted the machine’s frequency and that was why the bullet could not be found using Bell’s Induction Balance.

Improvements on the Induction Balance

Though the induction balance failed to live up to its expectations by saving the president, it was used as a prototype for more innovative types of metal detectors. Just like the first generation computers, metal detectors were really big and difficult to operate when they were first released, and they operated using vacuum tubes. These metal detectors were really useful and their popularity was on the rise. After World War I and II, metal detectors were used to remove unexploded bombs and landmines all over Europe.

While working on navigational systems, Gerhard Fisher a German-born scientist and the founder of Fisher Metal Detectors made an impressive discovery. The radio beams he was using for the navigational systems were usually distorted whenever there is an ore bearing rock in the area. He then used this technology on a small scale to help produce portable metal detectors.

Fisher was granted a patent for his invention in 1925, and he sold his first metal detector to the public in 1931. Fisher called his invention the Metalloscope. Geologists used this invention to locate ore, utility companies used it in locating pipes buried deep in the earth, and law enforcement agencies used them to discover concealed weapons while treasure hunters used the metal detectors to hunt for treasures.

Though, Fisher is not the first person to apply for a patent. The first person to apply for a patent is Shirl Herr in 1924, Shirl’s invention helped the great Benito Mussolini in recovering priceless artifacts from the bottom of Lake Nemi in 1929. Also in 1933, this same technology was used by Admiral Richard Byrd in his second Antarctic Expedition where he recovered artifacts left by early explorers in the region. Shirl Herr’s machine was effective up to 8 feet.

Development of Metal Detectors from the 1950s till date (History of Metal Detectors)

Fisher was granted the patent, but he was not the only person that worked on refining and perfecting the technology used by metal detectors. There is another name that bears mentioning when talking about metal detectors and that is Charles Garrett who is the founder of Garrett Metal Detectors. This electrical engineer wanted a metal detector that could satisfy all his needs but none of the metal detectors on the market could do that.

This propelled Garrett to creating his metal detectors, and he was able to successfully eliminate the oscillator drift and several unique coils. He secured patents on everything he created and this was what sparked the evolution of metal detectors into life. Here is a list of the top metal detectors you can purchase from Garrett Metal Detectors; Garrett Ace 250 Metal Detector, Garrett Infinium LS Metal Detector, Garrett AT Gold Metal Detector, and Garrett AT Pro Metal Detector.

There is an invention that changed the whole perspective regarding metal detectors and that is; transistors. This was the deal-breaker, and it was invented by John Bardeen, William Shockley, and Walter Brattain in 1947. Apart from transistors, other inventions like new search coils, discriminators, and wireless technology helped metal detectors become portable, lightweight, convenient to use, and deep earth seeking.

There are now wireless detectors, and this was made possible by XP Metal Detectors. They designed the XP DEUS which is the world’s first wireless metal detector. The wireless design of this metal detector allows for considerable gain in signal acquisition quality.

Signals and electromagnetic frequencies do not have to go through a wired link, they are now digitized by a mini electric circuit in the coil. There are three devices in the XP DEUS that communicate with each other using radio signals. These devices are; wireless search coil, wireless audio headphones, and wireless remote control.

Now there are hundreds of advanced models that you can choose from. There are specialty detectors for the various different niche in treasure hunting.

Other Inventions that improved metal detectors

As mentioned earlier, other inventions helped improve the quality and effectiveness of metal detectors today and some of them include

Discriminators: This came into the limelight around the 1970s. They use two electronically balanced coils outside the metal presence. The metal type affects the alternating current. With this invention, you can now avoid irons, nails, and other unwanted targets that the metal detector used to pick up while using it. Though some metals are quite similar to gold which your metal detector might pick up, a good example is a foil. These are very similar types of metals, and with the discriminators, your metal detector might not even differentiate between them. 

Pulse Induction: This is another invention that helped the innovation and development of metal detectors. Pulse inductions send high voltage pulse into the ground, and where there is no metal, the signals of the pulse disappears uniformly and returns to zero. However, when there is metal in the earth, it interferes with the speed at which the pulse disappears and gets back to zero. Different metals have different effects on pulse induction. For those that are going to saltwater areas, you have nothing to worry about because the salt composition would not affect this invention.

Fisher Labs

This is the first and biggest large-scale producer of metal detectors in the world. After 85 years of establishing this lab, it has remained relevant in the industry by improving its metal detectors using the latest technology available. The legacy of Gerhard Fisher is still alive in the lab he created.

Currently, the lab is owned by First Texas Holdings Corporation and its headquarters is located in El Paso, Texas. Several users of metal detectors also agree that the company is at the pinnacle of the industry with its ergonomic, ground balancing, user interfaces, and target separation ability. Here is a list of the top metal detectors you can purchase from Fisher Labs; Fisher F22 Metal Detector, Fisher Gold Bug-2 Metal Detector, Fisher F75 Metal Detector, and the Fisher F22 Metal Detector.

Final thoughts

The first patent for metal detectors was given to Gerhard Fisher, but he was not the first person to create a metal detector. It was first created by Alexander Graham, to help save the life of President James Garfield, but it failed to save the president. It was Alexander Graham’s induction balance that Fisher used as a prototype which helped him to create his metalloscope that received its patent in 1925. So we owe our developments in metal detectors to these great people.

With the constant improvement in technology, metal detectors would certainly continue to evolve. The changes from the induction balance to what we have today is unbelievable, and this would continue into the foreseeable future. Treasure hunters are very passionate about their jobs and they always believe that there is more, this would always lead to them establishing more innovative ways to seek for treasures and historic items. Treasure hunters, scientists, and inventors are those that keep influencing the future of metal detectors.