Pulse Induction Metal Detector
The Past and Future of the Pulse Induction Metal Detector
The biggest step forward in metal detection technology was the introduction of the pulse induction metal detector in the 1970s. Previously, metal detectors used a uniform, alternating low-frequency current. The first pulse induction metal detector used high voltage pulse signals instead, which identified the presence of metal more accurately and from further distances.
The real advantage of the transition to the pulse induction metal detector was its resistance to the effects of mineralization so that metals could be more easily located. These days, a pulse induction metal detector has incredibly high sensitivity to all metal targets, making it commonplace to go metal detecting near salt water, iron-based rocks and magnetic sand with no loss of accuracy.
The first metal detector was not actually invented to strike it rich, but to try to find the fatal bullet lodged somewhere in the body of an assassinated American President. Alexander Graham Bell was asked to build a bullet-detecting device, but his invention was not successful. The bullet that killed President James Garfield in 1881 was never located and the famous inventor did not develop his ‘electromagnetic induction balance device’ any further. It was left to aviation engineer, Gerhard Fischar, to progress the idea into a commercially viable portable metal detection unit, more than thirty years later.
The pulse induction metal detectors still have room for improvement. Numerous manufacturers are working to further enhance the ability of a pulse induction metal detector to ignore both conductive and non-conductive mineralization at the same time. Many currently hidden metals would be easily detectable if this method can be developed further. Some of the best metal detectors for all purpose requirements are still the VLF (very low frequency) metal detectors.
