SOLEN

Carefully weighed metal specimens are installed in a coupon rack and left in place for a given period of time, usually 90 days or more. The specimens are then removed, cleaned and reweighed. A corrosion rate, in mils per year is calculated from the weight loss, coupon size, metal density and length of time exposed.

Coupons are applicable to both open and closed recirculating water systems. Both types of systems should be monitored.