AlgoForce E1500 And Pi Discrimination

[Steve Herschbach]

We have a new player on the field in the form of AlgoForce and their new E1500 detector. One thing that is not getting as much attention as I would expect from a PI - full range target conductivity id. From the owners manual:

"For experienced PI users accustomed to estimating nugget size from audio cues, the AlgoForce E1500 can also help to estimate size or conductivity through its stable conductive target ID (0-99), even in highly mineralized soils. High single frequency VLF detectors typically struggle with signals on wet ocean sand, where PI detectors are far more capable of detecting through the salt mineralization. Capitalizing on its UltraFine pulse induction technology and stable conductive target ID (0-99), the AlgoForce E1500 excels on the beach, proving to be a versatile tool for searching fine jewelry, coins, rings, and other treasures." (Emphasis added)

The discrimination feature kicks in when using the pinpoint mode. Again, from the manual:

VIII. Pinpoint detected target (if needed) Enter the Pinpoint UI by pressing the Left/Pinpoint button in the Main Detection UI. In the Pinpoint UI, adjust Sensitivity with the Minus or Plus button. To retune the detection threshold due to ground variation or temperature drift, press the Left/Pinpoint button as needed. Perform Auto GB if needed by holding the Right/Auto GB button. Return to the Main Detection UI by pressing the Return/Auto FS button.

Pinpoint is a non-motion mode where the coil doesn't have to move to indicate a target. The detection signal gets stronger as the coil approaches the target, causing the audio (if audio output is on) or vibration (if vibration mode is on) to intensify. The Conductive Target ID (0-99) displayed in the Pinpoint UI remains stable even in highly mineralized soils. A higher number indicates a larger or more conductive target. To obtain an accurate target ID, it is recommended to follow these steps:

• Move the coil away from but close to the target.
• Ensure the coil is resting on the ground surface and press the Left/Pinpoint button to retune.
• After that, slide the coil on the ground surface until the target is positioned just below the center of the coil.

The target ID is also useful for assessing the target's shape. If the target ID fluctuates significantly when the coil is moved slightly off but still above the target, it likely indicates an irregularly shaped target, such as a bottle cap or a nail with a large head.

Target conductivity is not the same as VLF discrimination in that both ferrous and non-ferrous are conductive. Stuff that is small or low conductive reads low numbers and stuff that is large or high conductive reads high numbers. Ferrous can read anywhere depending on various factors, so the usefulness of the system largely depends on the nature and mix of targets you are working with.

Nowhere does the AlgoForce manual refer to ferrous versus non-ferrous discrimination. It specifically refers to the Conductive Target ID - in other words, a measurement of how conductive the target is whether ferrous or non-ferrous.

Most GBPI users have savvied to the fact that the high and low tones give a rough indication of target size. A hi or hi-lo tone usually means small or low conductive targets and a low or lo-hi tone usually means large or high conductive targets. You get ferrous either way, just small ferrous on one side and large ferrous on the other. However, in certain gold locations concentrating on hi or hi-lo tones only can be remarkably effective at cherry picking gold nuggets out of a nail pit. Most gold I find almost always gives a hi-lo tone.

Minelab employs a method where targets blank if ferrous, and Garrett the target grunts if ferrous. The Garrett method is preset, the Minelab method can employ a variable control depending on the model. What makes the AlgoForce different is instead of the "this or that", "yes or no" answer of two categories you get a full range indication, which with experience should lead to more nuance in what can be dug and what can be ignored.

PI discrimination is not the same as VLF discrimination. There are different aspects to it that require a savvy operator.  There are a lot of half truths and incorrect statements tossed around by people who don't know much on the subject. One of the most common claims I hear is that PI disc only works at shallow depths, and that the things you have to do to implement it give up the extra depth that is the reason for using a PI in the first place. This is based on some versions of PI discrimination and so can be true, but also reflects that the person making such statements is not well versed in all aspects of the subject. You can indeed discriminate to full depth with a PI, and in fact that is the only way I have been doing it for almost 20 years now. For more details on how pulse discrimination works see my long analysis at the thread below. No, it’s not VLF discrimination, but you’d be amazed what good PI operators can do with the capability they do have.

 

We have a winner in the Under 4 Pound, Under $2000 GBPI Challenge!

AlgoForce E1500 Specifications and User Manuals

Visit the new AlgoForce Metal Detector Forum

[Steve Herschbach]

[jasong]

49 minutes ago, Steve Herschbach said:

How can this possibly be real? I will refer you to a statement by famed metal detector engineer Dave Johnson. It is part of history now only available on the Wayback machine but has been in my mind for a long time:

DS: Are TID pulse units the hobby future? Or, what do you think will be the next great advancement in metal detector technology?

Dave: "About 1985 I built a real sweetheart of a discriminating PI unit, not very hot in air test, but it was simple, lightweight, powered by one 9 volt “transistor battery”, ran quiet in bad ground, had no bad habits, and you didn’t have to dig any trash. It morphed into a fully static TID machine which Fisher came close to releasing about 1989, but its reliance on fully static operation which was supposed to be an advantage, was in fact a fatal flaw for a TID machine. Stripped back down, it became the Impulse which was strictly all-metals.

 

This was way before my time so I'm probably missing some terminology, but what does he mean by a fully static machine? And in what way did that end up being a flaw?

I'm also curious if @Geotech could explain what the mechanism for TID was on this early PI, was it also done with just mono coils and not DD?

Interesting stuff. 

[Steve Herschbach]

47 minutes ago, jasong said:

This was way before my time so I'm probably missing some terminology, but what does he mean by a fully static machine? And in what way did that end up being a flaw?

I'm also curious if @Geotech could explain what the mechanism for TID was on this early PI, was it also done with just mono coils and not DD?

Interesting stuff. 

Static means non-motion, and if you are thinking normal motion mode detecting it is a fatal flaw. All detectors sold today work on a motion mode principle where they need to be in motion to detect. Why did they not see the obvious - make it the pinpoint mode, which are static / non-motion modes? Another mystery to me but in any case it looks to be that is what this machine is doing. As far as patents these days it reveals your method and encoding in firmware gives better protection in some cases. Or it is based on something Dave patented and expired already. Whatever, as long as it works. I hope. I am sure it will have limitations of some sort. There always is.

[Steve Herschbach]

More on static non-motion. It is all about the detector autotune function. Before autotune you had a fixed threshold and any motion of the machine affected that threshold, calling for constant manual retuning, usually via a threshold reset button. Then autotune replaced that button, with machines constantly automatically trying to bring the threshold back to the preset level. If you hover over a target it disappears. The White's V/SAT was innovative in that it gave you the ability to vary the retune rate via "Variable Self Adjusting Threshold". It is the all metal version of reactivity. I go into the subject and it's history in great detail in the article below.

PI went though a similar evolution from manual tuning to autotune threshold as anyone can see fast if you simply stop the coil over a target. Most PI detectors have no pinpoint no-motion mode at all.

 

[338Edgeshooter]

A stable target ID in a PI detector and pinpointing will be amazing for tailings and other iron infested spots if it works as stated! I cant wait for some of our experts on DP to get thier hands on the AF E1500! 

[Jim in Idaho]

Slightly off the subject, Steve....that display kinda reminds me of the DFX Signograph.

Jim

[Steve Herschbach]

Target id for some nuggets and Aussie coins here....

https://www.prospectingaustralia.com/threads/algoforce-e1500-new-pi-detector-from-ex-minelab-engineer.42049/post-676638

[phrunt]

I'll take mine to the beach not too long after getting it and test a few targets on the surface then bury them and see how well the Target ID works on a beach, I'll snag some video of the process, in my usual raw unedited way, call me lazy 🙂

 

[Knomad]

Interesting,

Any info on Price and Availability in the U.S.A.?

Nice to see someone thinking at least a little out of the box, if performance is competitive, and it can use legacy coils it could be a winner if at a good price, and it sounds like they are trying to keep price down, NOW THAT is Different.!