Corrosion coupons

Definition

Corrosion coupons are metal samples exposed in a system and later weighed to quantify metal loss and compute a corrosion rate. They allow quantitative interpretation of corrosion via MPY.

A coupon’s weight loss, area, density, and exposure time feed the MPY formula to express corrosion as thickness lost per year. The recommended exposure is roughly 90 days so passivation can establish and the result reflects long-term behavior rather than initial transient activity. Coupons and probes let operators interpret corrosion quantitatively rather than guessing from a failed part.

Related concepts

Mils Per Year (MPY) · Corrosion Rate Interpretation · Electrochemical corrosion

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Part of The Blueprint of Water · 📏 measurement