When designing distributed forced-current magnesium anode systems. The effective soil flag resistivity along the section to be protected must first be known. With this data, the ground resistance of a single magnesium anode can be calculated using the method described. The applied voltage can be selected and the spacing of the magnesium anodes calculated according to the following principles. First, the existing potential to ground along the protected section must be known. Thus, at the intermediate point between the magnesium anodes, the change in ground potential required to reach a minimum pipeline potential of -0.85W (relative to the near ground steel sulfate electrode) can be determined. The well resistance of all magnesium anodes is then calculated. Taking into account the resistance of the junction cable and the reverse voltage between the pipeline and the magnesium anode, the voltage and current required for the cathodic protection grab device can be calculated.

What should be injected is if a distributed magnesium anode system powered by an electrical device covers a considerable distance. The voltage attenuation due to the voltage drop (the current flowing through the resistance of the cable) in the junction cable will cause the voltage applied to the magnesium anode farther away from the emitter to be lower than the voltage applied to the nearby magnesium anode, which should be considered at the design stage. If the voltage difference is significant, an equal degree of protection can be obtained on the lines between the magnesium anodes in a distributed magnesium anode system. It is necessary to reduce the distance between magnesium anodes.

In determining the distance between magnesium anodes in a distributed system, the i-plus effect of the ground potential change at the midpoint of adjacent magnesium anodes is an important consideration. For example, after applying the design voltage to the magnesium anode. At the midpoint between the two magnesium anodes, the change of ground potential generated by one magnesium anode and the change of ground potential generated by the other magnesium anode is also 0.iv. The total potential change at the midpoint is 0. 2V. This must be taken into account when designing the magnesium anode spacing.