Control Units First
Most CP calculation errors come from mixing amps with milliamps, inches with feet, or total area with exposed area.
Cathodic Protection Formulas
These calculation references support cathodic protection design, testing, troubleshooting, and interpretation. Use them to practice the math behind current demand, rectifier output, anode life, surface area, voltage drop, and polarization change.
CP calculations are only useful when the units, assumptions, and field context are controlled. A correct calculation does not automatically prove adequate CP.
1. Electrical Calculations
These formulas support basic circuit interpretation, rectifier troubleshooting, voltage drop checks, and resistance calculations.
2. Current Demand Calculations
These pages help estimate how much protective current may be required based on exposed area, coating breakdown, and selected current density.
3. Surface Area Calculations
Surface area calculations are often the starting point for current requirement estimates. Always keep diameter, length, radius, and area units consistent.
4. Anode and Design Calculations
Anode calculations help estimate output and service life, but field performance still depends on electrolyte resistance, installation geometry, anode condition, and current distribution.
5. Polarization Calculations
Polarization calculations compare related potential readings. They require valid measurement conditions, matching reference electrode scales, and consistent test locations.
How to Use These Formulas
Separate Math from Judgment
A correct calculation does not automatically prove adequate CP. Field measurements, current distribution, criteria, and site conditions still control the conclusion.
Practice Repeatedly
Use the formula pages first, then test recall with the CP calculations practice questions and interactive quiz.