1. n. [Drilling Fluids]

An abbreviation for corrosion coupon, a specimen of test material to be used in a corrosion test, usually a metal strip or ring shaped to fit into a testing cell or between joints of drillpipe. Rings, or coupons, are weighed before and after exposure, and weight loss is measured. They are also examined for pits and cracks. Corrosion products are analyzed to define the type of corrosion reaction.

Synonyms: corrosion coupon

See: anode,  hydrogen sulfide,  stress corrosion cracking,  sulfide scavenger

2. n. [Well Workover and Intervention]

An abbreviation for electrical coupon, an instrument used in a corrosion test to determine metal loss. It directly measures the increase in resistance of a metal as its cross-sectional area is reduced by corrosion. At suitable times, once the readings are obtained, these numbers are converted into corrosion rates (mpy). An electrical coupon is also called an electrical resistance probe.