How do detectors work

Ground Mineralisation A target in low mineralised ground can be detected deeper than a target in highly mineralised ground. The level of ground mineralisation has a significant influence on detection depth.

Target Shape Circular shapes like coins and rings can be detected deeper than long thin shapes like nails. Target Orientation A horizontal coin e. Target Material High conductive metals e.

Email address:. Will be used in accordance with our Privacy Policy. Log in. How Do Metal Detectors Work? Tracking Ground Balance — The detector continuously adjusts the Ground Balance setting while detecting. This ensures that the Ground Balance setting is always correct. Minelab detectors use exclusive advanced technologies for superior ground balancing capabilities that cannot be matched by any other detectors. By accurately identifying a buried target you can decide to dig it up or consider it as junk and continue searching.

Variable discrimination — The simplest type of discrimination which uses a control knob to adjust the level of discrimination. Notch discrimination — Allows specific target types to be accepted or rejected. Smartfind — The most advanced form of discrimination. Target IDs are plotted based on both ferrous and conductive properties on a two dimensional 2D display.

Individual segments or larger areas of the display can be shaded to reject unwanted targets. The simple answer is "as deep as the diameter of the coil". So detectors with larger coils will detect deeper. However, detection depth also depends upon detector technology and many environmental factors. High conductive metals e. Multi-IQ achieves a high level of target ID accuracy at depth much better than any single frequency detector can achieve, including switchable single frequency detectors that claim to be multi-frequency.

This enables maximum target sensitivity across all target types and sizes, while minimising ground noise especially in saltwater. There are presently only a handful of detectors from Minelab and other manufacturers that can be classed as true multi-frequency, all of which have their own advantages and disadvantages.

Minelab has been carrying out detailed investigations into this in recent years. Just as you can colour in a map with many colours, the minimum number to differentiate between adjacent countries is only four. When it comes to frequencies in a detector, how the frequencies are combined AND processed is now more important than how many frequencies, for achieving even better results. The traditional metal detectors , which works according to electromagnetic technology,.

Think of it as the armrest of the machine. It stabilizes the metal detector as you move it around. An object with high resistance is going to have a smaller phase shift. There are many devices that work using this technology like Gold Monster , Impact , and Minelab Vanquish …etc.

This spike lasts a few microseconds millionths of a second and causes another current to run through the coil. The ability to distinguish different metals is due to a principle called phase shifting. Without getting too detailed, the frequency of the transmitter coil is different from that detected by the receiver coil.

This is because each type of metal has a different electric resistance, which affects how easily electricity flows through it. By knowing the resistance of each material, and hence the phase shift, the detector can tell which type of metal is below the ground. This is called discrimination in metal detecting. As an additional benefit, many VLF detectors also allow you to filter metals you don't want to find. This is achieved by using a knob to set a certain phase shift threshold.

If you want to detect a specific range, some VLF detectors will allow you to create notches or phase shift ranges , or even multiple notches. As you can tell just by looking at them, modern metal detectors are much more than just two coils of wire and a battery. Other important features include:. You could argue that the origins of the metal detector date back to James Maxwell, who discovered the equations that are essential to their operation.

It wasn't until the late 19th century that scientist began using these important theories to create machines for detecting metal though.

The first "handheld" model was invented by a French man called Gustave Trouve in , while Alexander Graham Bell invented a machine to detect a bullet lodged in President James Garfield a few years later. It wasn't until the s that the development of metal detectors began to pickup pace though. The first patent for a metal detector was awarded to Gerhard Fischer in , although it was improved by a variety of inventors over the years.

Lieutenant Jozef Stanislaw Kosacki, for example, refined the design into a machine that was more practical - albeit considerably heavier than modern machines. Today, the top models have features such as a computerized design and integrated circuit technology to allow the user to fine-tune their detection parameters. There are different types of metal detector, and one of the most important for hobby detecting is the pulse induction PI detector.

Unlike VLF detectors, these usually have just one coil that acts as both the transmitter and receiver. Short pulses of current are passed through the single wire, which creates a magnetic field. Once the pulse is switch of, the field collapses which causes a spike in electricity, resulting in another short-lived current.

If the detector is near a metal item, the detector's sampling circuit picks up the opposite magnetic field. It can detect the metal as the second pulse called the reflected pulse takes longer to fade away.

While pulse induction technology provides greater depth and decent sensitivity for gold, there are a few downsides. Most PI detectors aren't suitable for use in urban areas, as they can't identify or ignore iron "trash. They are better for hunting in rural locations though, and can provide a deeper search. They are also great for beaches and other environments that contains highly conductive material.

There are also beat-frequency oscillator BFO metal detectors. These are the cheapest and least complex. Many industrial detectors, for example, have a three coil design. This configuration allows the instruments to detect tiny pieces of metal.