Pulse Induction Metal Detector - The Best Detectors for Finding Gold!

The pulse Induction metal detector is the best metal detector for finding gold in the WA Gold fields because;

  • PI Detectors do not respond to the iron mineralization commonly found in the WA Goldfields e.g. magnetite.
  • This is strongly evident in magnetite hotrock conditions which will cause the VLF to overload but not impact on a PI. A nugget of gold next to a magnetite hotrock will be missed by a VLF detector but the positive gold response will be picked up by a PI detectors.
  • They have increased depth over VLF due to the increased power that can be generated to the coil which creates a stronger signal.
  • Pulse Induction metal detectors are designed specifically for the conditions found in the goldfields of Australia.

As outlined in the Compare metal detectors page, it can be seen that the PI is the best metal detector for finding native gold nuggets.

How do Pulse Induction Metal Detectors Work?

The Pulse Induction Metal Detector generates a brief high current pulse into the ground via the coil transmit wiring. When the current is flowing it generates a magnetic field that expands outwards from the coil.

When this magnetic field encounters a metallic object it changes the current flow.

When the current pulse is turned off the current flow generated by the object generates back to the coil creating the target sound.

The resulting signal (target sound) returned via the receive coil is amplified, sampled and analysed.

This cycle is repeated on an ongoing basis hundreds to thousands of times per second.

Why Can You Find Small Pieces of Iron Easily Yet Miss Small Gold?

It is important to note that the signal strength and duration of the signal varies from object to object. Iron produces a larger and longer signal than gold and that is why a similar sized piece of iron will produce a stronger signal than gold and be easier to detect!

So if you are wildly swinging your detector and finding small pieces of iron like staples and no gold, remember it may be the technique you are using that is preventing you detecting those small pieces of gold. It does not follow that just because you are finding small fragments of iron you will also always find the small gold!

Pulse Induction Metal Detectors Main Advantages



Mineralised Ground

Handles mineralised ground better than a VLF. Heavily mineralised ground will overload the circuits of a VLF.


Generally greater depth particularly in mineralised areas.

Hot Rocks

Handles hot rocks and mineralisation better than VLF.

Small Nugget Detection

In noisy mineralised areas the PI has an advantage over the VLF.

Monoloops Only Used on PI metal detectors.

PI Metal Detectors Designed to Find Gold

Monoloops are only used on PI detectors and they can be more sensitive to smaller gold.

For a further information about coils see Metal Detector Coils

In general terms the PI Metal Detectors have been specifically designed and built to find native gold nuggets.




Price of PI Machines are much higher than the VLF machines

Electrical Interference and EMI

More sensitive to Electrical and Electromagnetic interference.


PI Machines do not reliably discriminate between different metals.

The most reliable discriminator is you, by digging the target!

A Signal can be Generated by some hotrocks In PI Detectors

PI Machines will generate a response to the basalts and banded jaspers in WA

Some hotrocks will generate a weak target in the WA goldfields but the target dissapears if the coil is raised so deeper hotrocks do not generate a notieceable signal.

Earth Field Effect signal (EFE)

This is the noise caused by voltage generated by the coil moving through the earths magnetic field.

Although there is an attempt to elimintate this in the design of the detector it is seldom eliminated.

This signal is particularly noticeable at the end of each swing of the metal detector.

Other sensitivity to noise

PI Machines can create strong ground noises in some conditions such as:

- Where there is a clay base.

- Where there is a accumulation of buried ash from fires.

- Where there is concentrations of Maghemite (Ferromagnetic ferric oxide)

What Should You Base Your Purchase Decision On?

That is also a difficult question which will depend on what you want in a metal detector and what you will use it for.

If you want to specialise in finding gold nuggets in Western Australia as more that just a once a year hobby, and PRICE is not your key issue then a top range Pulse induction metal detector like the Minelab 4500, 4800 or 5000 is a very good choice.

Remember too that if you look after this machine it will have a good resale value after use - check out sales on ebay or other sites!

Dont waste your time on lesser or old technology - its just false economy.

Alternatively a Second hand Minelab 4000 or 4500 will save you $000's and still do as good a job for you.

For example now the Minelab 5000 series has been released, Minelab 4500 machines are readily available second hand for about $Aud4500. 

Minelab 4000 machines range down from these prices.

A new Minelab 5000 metal detector will set you back $Aud6700 - the technology of the Minelab 4000 and 4500 is excellent for finding gold in Western Australia, but at a much lesser cost.

If you just want to use a metal detector occasionally when you are travelling to look for a few coins or relics with the odd trip gold prospecting then a good VLF Detector or a lower price range PI Detector might be quite OK for you.

If you want a waterproof detector for beach hunting or underwater detecting then you can also get models that are designed for land and underwater use.

Compare Metal Detectors

Here is a link to a page where you can compare metal detectors.

That page also has a link to software that enables you to make an informed decision on any question you would like to ask, including the type of metal detector that is best for you.

If you review this page and the VLF metal detector page it will help you make a more informed decision based on your needs and the criteria you want to use when selecting a metal detector and coil combination. 

Return to Gold Prospecting home Page from Pulse Induction Metal Detector page.

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