# A simple galvanic metal identification instrument can be built extra cheaply



## goldmindery (Nov 24, 2021)

Simple galvanic PM tester .....All you need is a penny or copper wire, 50 ml of tap water, a plastic cup, a digital voltmeter, couple of alligator clips.
The penny/wire is the anode to the meter; the unknown metal is the cathode negative ground lead to the meter.
Set the copper about one inch from the other metal both partly in the water. Consistent values I have obtained are:
gold = ~170 mv or less depending upon karat
silver sterling = ~300 mv [spoon]
aluminum foil = ~400 mv
lead = ~500 mv
zinc = ~600 mv
other metals haven`t tested yet, too busy...try it out... see if it works...it takes a few seconds to settle at the values.. n bye.


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