Corrosion monitoring in cooling water systems is used primarily to ensure adequate water treatment programs. Protecting the owner’s equipment should be the primary goal. In many instances, there hasn’t been enough importance placed on accurately measuring and reporting corrosion results. Most corrosion systems are installed in convenient locations and many of those locations do not properly provide an accurate assessment. This paper will describe various methods and programs from standard corrosion coupons to various online corrosion monitoring systems and other techniques.