Gordon: Here is one of the articles from internet:
Quote:How do I calculate the number of anodes for my system?There are some fundamental steps, which must be applied in the design of a sacrificial anode system. However this is a guideline only, each application is different.1) Area to be protected needs to be calculated.2) Polarized potential. NACE Standard RP-01-69 states that for a steel structure in a neutral environment, polarization to -0.85 V versus Cu-saturated CuSO4, is required to protect the structure. The current density needed to achieve this potential is used in the design of the system.3) Current demand. This is calculated as a product of required current density and area. The current demand varies for steel in various environments, thus it is important to assess the different environments steel may be exposed to and complete separate calculation for each environment.4) Anode consumption. Total required weight of anodes is determined from known consumption rates for the calculated current demand. Consumption is necessary in order to supply current for protection. 5) ...............UnquoteOr we are not on the same boat?