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How Make A Serious Comparative Tests Procedure

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First rule Blind tests are mandatory to be serious.

Second rule if you do not agree refer to rule number 1 😊

The purpose of this playground, and not to take into account the feeling of the prospector. It is too easy for a participant to indicate that he is correctly detecting the target. But in general he does not detect it or he thinks to detect it. It often detects a ground effect.

During our long experience and our meetings with prospectors at the beach, we realized that the prospector was often influenced by the pride placed in his detector. This is why we have implemented this drastic and non-falsifiable comparative tests procedure.

Of course for this test you have to be 2 people.
A person who hides targets and a person who tries to find them. The depth tests can be done simultaneously.

It is obvious that here are static tests. The reality is even more difficult! See for yourself the catastrophic results ....

Document here :







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Count of correct answers: ferrous targets + 1pt / gold targets + 3pts.
Counting the wrong answers -1pt.

Note : Those who did not answer scored more points than those who were convinced

6 squares of 1 meter x 1 meter
Each square containing 10 boxes.

Possibility on each square to have 0 or 1 or 2 or 3 targets

Indicate whether there is a gold or iron target or a ground effect or iron mixed with gold, or nothing at all and do this for each of the boxes of all the squares.

Advantages :

- Impossible to lie
- Impossible to guess by chance (millions of possibilities)
- allows to compare the detectors on all the difficulties encountered.
- allows to perform depth tests simultaneously.





There were 66 prospectors, and 48 prospectors abandoned.



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Thats pretty cool 1 thing retain my attention 😅😅:



All other competitors abandoned (66 prospectors / 48 abandoned)




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Thanks for sharing and all of the time and effort that went into the field test. Hats off to you and those who helped.

The test from my point of view shows One's knowledge of his machine is what makes the difference. A very close Second and Third would be having the correct machine and familiar with those hunting conditions.


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Yes I agree with you Alexandre , a serious MD test must be a blind test. If the tester knows where the target is buried and the kind of target buried , in most cases he will tell that he detects the target, even its detector cannot do it. As you said he THINKS that he detects it but it is a kind of psychological "auto suggestion" process ( sorry it is in French ) . The MD tests must be done very scientifically with a very strict procedure as you have done above . Doing this with many detectors of different brands on my own bed tests , I arrived to the conclusion that the max detection depth for a VLF detector in moderated mineralized ground is always around 28/30cms for a 10Centimes napoleon3 ( 10grams french copper coin ), no more ,whatever the detector brand is  . Tthis is just logical because the electronic/electromagnetic physical laws are the same for all the machines.... The last test that I did was with the Nokta Simplex+ , and the result was again 28cm on this 10C Napoleon coin.

By the way I am looking forward to see a Fisher PI coin/relic  machine coming after the impulse AQ and the Terra , if this is technically possible .And I am looking forward to see a machine beating the 30cm depth on the 10Cent Napoleon 3  ( with a very good iron disc of course ) , I have never found one up to now ….

thanks , Alain



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The sensitivity and range of the VLF will depend on the frequency and also the real ..- Correct / not maximum / detector settings for the given degree of terrain mineralization ..
  So feel:
  low-mineralized terrain approximately 85-90% reach, / compared to airtest at the same settings /
moderately mineralized terrain 75-80% reach,
and about 55-60% reach in extreme mineralization
Of course -from real-optimal Vlf detector setup for given terrain type.
So the actual performance of Vlf in heavily mineralized terrain can eventually be only 35% compared to the maximum detector setup ...- which you cannot use here ..
The detector frequency alone gives you a certain degree of sensitivity for the conductivity of the object.
Higher frequencies are still several times more sensitive to low-conductive objects - for example, gold

..Multifrequency maintains a more balanced sensitivity to all types of object conductivity


Therefore, I consider a PI detector with good iron discrimination as a much more powerful detection tool in difficult terrain conditions than a VLF detector.

So the new PI detector ..... Fisher Impulse AQ, can say a lot in deep detection ..

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El Nino your post is very interesting thanks. On my bed tests I have 70% reach , for example on a french 10cent Napoleon 3 10grams copper I can detect it at 40cm in the air , and it reduces to 28cm in the ground, this , it is true for all brands of machines that can run a low frequency under 10khz. For example 5khz or Multi with the equinox. 

So this is my challenge , it is very simple , go deeper than 28/30cm with a 10C Nap3 coin  …. 

Actually I am wondering it the impulse aq can be used on moderated mineralized soils. If this is possible , then an AQ will probably go further that 30cm in the ground . But from what I read in this forum it looks like that the AQ has been designed only for salted beaches  . But wait and see , the real tests will answer to the question ...

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