Definition - What does Coupon mean?
A coupon is a simple and highly effective tool that gives a quantitative estimate of corrosion rates that take place within a specific operating system. These coupons also provide a visual signal of the corrosion type that may be occurring in the system under observation.
Coupons can precisely monitor the corrosion rate in any critical environment. Benefits include:
- Lower repair costs
- Easier maintenance
- Measurement of material failure
A coupon is also known as a corrosion coupon, a corrosion monitoring coupon or a test coupon.
Corrosionpedia explains Coupon
Coupons provide cost-effective corrosion monitoring of an operating system and facilitates corrosivity measurement in a system in the most accurate manner. This is usually done through the observation of the corrosion rate measured in mils per year of a coupon exposed to the system. With this analysis, valuable data can be extrapolated about the life expectancy of materials.
Coupons are pieces of metal that are available in varying shapes, sizes and materials. They contain the same chemical composition as the equipment to be monitored. Corrosion coupons are exposed to a corrosive environment similar to that in process facilities for a specified period of time and can give visual signs of the corrosion rate and type.
Such coupons are usually stenciled with a unique serial number for easy identification.
The three most common types of coupons are:
- Strip ¾ - This is the most widely used coupon for all corrosion evaluations.
- Strip ½ - This is also widely used with narrow ports or low-pressure equipment.
- Disc - This coupon type is applied in multiple or stacked monitoring applications.
With the aid of erosion and corrosion monitoring coupons studies can be conducted to meet the highest standards level.