This test calls for a sample of the material in question to be placed in an airtight container with three
coupons of different metals—
silver,
lead, and
copper—that are not touching each other or the sample of the material. The container is sealed with a small amount of de-ionized water to maintain a high
humidity, then heated at 60 degrees
Celsius for 28 days. An identical container with three metal coupons acts as a
control. If the metal coupons show no signs of
corrosion, then the material is deemed suitable to be placed in and around art objects. The Oddy test is not a contact test, but is for testing
off-gassing. Each metal detects a different set of
corrosive agents. The silver is for detecting reduced sulfur compounds and
carbonyl sulfides. The lead is for detecting organic acids,
aldehyde, and acidic gases. The copper is for detecting
chloride, oxide, and sulfur compounds. There are many types of
materials testing for other purposes, including
chemical testing and
physical testing. ==Development==