Can a detector be set only to respond to gold?
No. There are too many variables with exact alloys and sizes to pin it down tightly enough to dig only one type of metal. For example, a large piece of gold may read high on a display or audio discrimination scale and a small piece of gold may read low on that same scale. Gold with some copper, silver, or platinum within its natural alloy will indicate differently. And other metals with similar electrical characteristics may read identically. Lead and aluminum are the most difficult common trash metals to eliminate. Even with the most sophisticated detectors available, expect to dig some trash. But a good discriminator increases the odds in your favor.
