You may have to do your own air test to get the numbers for your machine. The numbers will be in the ball park and might shift depending upon tuning and soil conditions.
If you look at the numbers most indicate something good. You have to decide whether your going to dig all the solid signals or not and pass up on some good stuff.
There is a tremendous amount of good items you will pass on using an ID machine and there still is a fair amount of junk that registers outside the junk numbers.
I have noticed that anyone who uses an ID machine, I can come behind running all metal mode, listen only to the tones and show you a handful of coins that person missed.
Zoomer on one of the other forums finds gold with his BH 3300 all the time, his motto is dig it all, leave nothing. If you want gold dig the junk. Lot's more work but, 1 gold ring
is worth more than going home with a popcket full of pennies. I am like zoomer, digging it all.
Hunted a schoolyard near me to death with 5 different Tesoros, Teknetics Delta & Omega, Fisher Coinstrike...found several hundred coins, should have been cleaned out. At least it seemed like it.
Took my PI in there many times afterwards and found hundreds of clad coins, PI doesn't do well with pennies and that's fine with me.
Just a small sampling of what the PI found
One area I didn't hit very hard at this schoolyard with the PI due to all the junk, gave up more clad the other detectors completely missed.
Used my Detectorpro Wader
Ok so that area must now be cleaned out for sure?
Took the 1994 Discovery Treasure Baron into the same spot to double check.
Alrighty then, now there can't be much of anything left?
Took the Minelab X-terra 70, just purchased in there to find out.
Here's what it found
Wonder if "now" there is anything left?
My new way of thinking is I have three good detectors to get the job done. Might be good to take the PI in first and scope the area out of clad and jewelry.
If I do somewhat good, come back in with the Baron and then with the X-terra, dig the pennies and grab the rest.
Does go to show you, not all places are hunted out and many detectors can't find it all. Many ID machines just plain miss alot and you can't rely on target ID,
especially if you live in Canada.