Sacrificial anode:
Advantages:
1, no need for external power supply
2. Little interference to adjacent metal structures
3. The workload of management and maintenance is small
4. The cost of work is proportional to the length of protection
5, the protection current distribution is uniform, high utilization rate
Disadvantages:
1 High resistance environment is not suitable for use
2, the protection current is not adjustable
3. High requirements for the quality of overburden
4, consumption of non-ferrous metals, need to be replaced regularly
5, can not be used when the stray current interference is large
Forced current:
Advantages:
1. The output current is continuously adjustable, which can meet the requirements of larger protection current density
2 is not limited by ambient resistivity
3. The bigger the project, the more economic it is
4, the pipeline anticorrosive coating quality requirements are relatively low
5, long service life of protection device
Disadvantages:
1. Reliable external power supply is required
2, large interference to nearby metal structures, especially near the auxiliary anode
3 A cathodic protection station is required for daily maintenance and management
Minimum device cost cannot be reduced when small current is required