1) The Pro is a nice machine but has a quirk or two. It will ID some square pulltabs and gold rings as nickels and will ID some silver rings and zinc cents in the dime/quarter range.
2) When hunting for gold rings in parks & schools... Notch out, round and square tabs and dig the foil and nickel signals to find those pretty AU rings. Your chances are better if you go this route.
3) I've seen rings do the "bounce" so be careful...
4) About 85% of rings are knocked out at the foil and tab setting. You have to dig a lot of junk to get them. However, a percentage of gold rings will fall into the nickel category so dig all these. Many silver rings will come in at the high end of the scale. Gold coins also disappear right after you discriminate out foil.
5) Here are my CZ-6a gold ring test results: 3=round tab, 30=foil,
4=square tab, 6=nickle, 0=zinc, 1=high coin. In
addition, I had five other non-ring gold items all classify as foil. My best ring worth over $1000 is the one that read as high coin.
6) Test all the gold rings you can, yellow, white, 18k, 14k, 10k, this will give us a good sample of what's out there. I have already tested 30 myself. Example: 5=round tab, 8=sq. tab, 9=foil, 2=zinc, 3=nickel, 1=high coin.
7) My tests so far show that most small 14k and 10k rings fall under foil. Medium and large 14k and 10k rings fall under tabs. I did have one large 10k ring read as zinc. I tested a 23k band that I had found several years ago and it also read as zinc.
8) White gold will most likely read as nickel and more in the foil range, but I've never had one read as iron. The same goes for platinum depending on what it is alloyed with.
9)My CZ-5 found a gold ring which was lost for 21 years. It was at 2" and read as a square tab. The signal was solid. No jump. It was a medium man's wedding band of 14k gold.
10) If you want to find gold, you're gonna have to dig some
trash. Try digging your foil signals and some square tabs as well.
Dig readings that bounce around from foil to tabs too.