value of air testing

If you are after gold jewelry, you have to dig just about everything above iron as the makeup of different gold will come in just about anywhere from foil to nickel and pulltab and even zinc. This is with any detector from an entry level one to the top of line detectors. Some say it can even come in at the upper iron level too, but so far I've never tested any that have.

one thing that the video doesn't make mention of (for white's users) is the usefulness of the DC phase reading.
The DC phase on the DFX is the display of the non-normalized 15khz VDI while in pinpoint mode. For example, usually, pulltabs, while reading similar to gold jewelry in the discrimination VDI, the DC phase of pulltabs usually reads 2 to 2.5 times higher than the disc. VDI, whereas gold usually reads a lot lower, and closer to the normalized AC(discriminate) VDI.

I recently dug a 3g 10k ladies class ring that read a VDI of 9-10, but had a DC phase of 15. Right before I had dug it, I had hit a signal that also gave me a 9-10, but the DC phase on it was 22. In effect,when I got the low DC phase reading on the ring, I was 90% sure that I had *at least* found something that wasn't foil before I dug it.