First

[macgiver]

Hi everybody,
I am new in this Forum. I am French, so excuse my bad english.
It is many days I read this Forum and it is a very nice metal detector Forum...
I make detection with an Xp GoldMax and i want to try Pulse Induction, so i am very interested about PI technical questions...

Thanks to every body.

[mikebg]

Hi Macgiver
You should read this book
http://www.geotech1.com/forums/showt...-Detector-book!
and if you have questions, the authors will answer.

[macgiver]

I buy it now...
I have a question.
Difference between Minelab SD2000 & SD2200 is, SD2200 is able to discriminate iron with DD coil.
I am searching why DD coil discriminate and not monoloop with same electronics?
I don't see anybody speaking about that...

[macgiver]

Could you give me the link to buy this book?
I am in France.
Thanks.

[kt315]

UNDERSTANDING THE PI METAL DETECTOR

http://www.nuggetshooter.com/article...detector2.html


Finally, Discrimination on a PI
Due to the nature of the signals caused by different objects, it is extremely difficult, or put another way, almost impossible to build a good discriminating PI.
Since the time it takes for a target signal to decay can vary because of the size, shape, and chemical makeup of the object, then any type of later sampling will not produce a reliable form of discrimination.
Many PI's rely on the ability of an adjustable delay whereby the operator can simply adjust the delay longer to see if an object is a piece of gold or not. If the delay is increased and the signal from an object disappears, then the operator can assume the object is made of a lower conductive material such as gold. This is acceptable for those hunting something like gold rings, but does not work well on gold nuggets. larger gold nuggets can produce a much longer delay, so any attempt to use this delay technique will result in one thinking a large gold nugget to be junk.
Another concept used on a PI for discrimination is to sample during the "on" time of the pulse. Any target will produce a slight change in the signal seen at that time as well as a change when the normal target sample is taken.
If the analysis is done correctly, then one can use both the "pulse on" and "pulse off" signals and get a better analysis of a target. This type of design can lead to a better form of discrimination. However, few if any PI's are actually using this technique.
Regardless of the technique used, no form of discrimination is perfect, and, most likely, never will be. Some techniques are better than others, but all can be fooled, and this is true of both PI's and VLF's.

[Davor]

Could you give me the link to buy this book?

It is sold directly by the authors. Send Qiaozhi a pm for details. I'm about to get one as well as soon as I sort out my paypal account

[Qiaozhi]

Could you give me the link to buy this book?
I am in France.
Thanks.

The details are here ->
http://www.geotech1.com/forums/conte...metal-detector

You can also find this information by clicking on Articles > Inside the Metal Detector

[macgiver]

Thanks for you answer.
Do you know more about how it discriminate? Is it a ratio between "ON" and "OFF" time slot or something else...?
Do you have a more detailled ?
Regards

[Sergey_P]

US5506506
http://www.lammertbies.nl/electronic..._detector.html
http://www.itep.ws/pdf/DRDCsoil2009-Terrascan.pdf
http://www.serdp.org/content/downloa...1355-FR-01.pdf
http://www.itep.ws/pdf/proceedings.pdf