Important Notes For Testing - Sigma Metalytics Precious Metal Verifier Quick Start Manual

Important Notes for Testing

Density Testing
It is critically important to confirm a sample's density in addition
to testing its resistivity. Every precious metal alloy has a unique
combination of density and resistivity; by only testing one aspect, the
sample is only partially confirmed to be consistent with the genuine
alloy. The PMV Original is only testing resistivity and it is up to the user
to confirm density separately.
There are many ways to confirm a sample's density is correct.
Whatever method you use, the sample should be the right weight and
the right size for the alloy. If your sample has published specifications,
the simplest way to confirm density is to weigh it and size it (measure
thickness and diameter or length and width) and confirm that your
sample matches the published specifications.
Correct Alloy Setting
Some alloys are unique to specific types of coins, and it is important to
test a sample on the correct alloy setting. For example, the American
Gold Eagle has a unique alloy of 91.67% gold, 3% silver, and 5.33%
copper. It will only test properly on the American Gold Eagle setting, not
the other 91.67% gold settings.
Modern Sandwich Coins on 90% Silver Settings
Modern sandwich coinage will read within the acceptable range on
the 90% Silver Bal Cu setting. Modern coinage is designed to have
the same resistivity to ensure they work in coin machines with older
coinage. The best way to ensure your quarters are 90% silver is to check
their density (weight and size) in addition to the resistivity test. Below
are the specifications for both modern and pre-1965 quarters.
Checking Calibration
If the PMV is giving inconsistent results or odd readings, and the tests
are being performed correctly (on the correct alloy setting, using
the correct sensor, sample is within minimums, etc.), then check the
device's calibration (Page 6). If the device's calibration is not correct,
then contact us immediately for service. If the device's calibration is
correct, then the sample is highly questionable.
Magnetic Samples
Samples that are highly magnetic will cause the device to enter a
constant re-calibration state when placed on the sensor. If the device
is repeatedly asking for recalibration when a sample is placed on the
sensor, then use a magnet check if the sample is magnetic. Genuine
precious metal pieces are not magnetic.
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