Formulas

Anode System Life Calculations (Capacity vs Consumption Rate)

Formulas for calculating sacrificial anode system life using either consumption rate or capacity constants.

Cathodic Protection Design Anodes CP 3

Attenuation (Cathodic Protection Current Decay)

Key attenuation formulas used in CP analysis including attenuation constant, leakage resistance, and characteristic resistance.

Cathodic Protection Attenuation Pipeline Analysis CP 3

Cathodic Protection Current Requirement Calculations

Formulas used to estimate cathodic protection current requirements using surface area, current density, voltage shift methods, and conductance relationships.

Cathodic Protection Current Requirement CP Design CP 3

Coating Conductance and Specific Coating Resistance

Formulas used to calculate coating conductance, specific coating resistance, and current requirements from interruption test data.

Cathodic Protection Coating Conductance Pipeline Testing CP 3

Meter Loading and Pipe-to-Soil Potentials

These formulas cover temperature correction, meter loading, true potential, IR drop, polarization shift, and reference electrode conversions for pipe-to-soil potential work.

CP 3 Pipe-to-Soil Potentials Meter Loading IR Drop Polarization Reference Electrodes

Meter Loading and True Potential Correction

Formulas for correcting pipe-to-soil potential measurements affected by meter loading using dual-input impedance readings and voltage-divider relationships.

CP 3 Meter Loading True Potential Pipe-to-Soil Potentials Instrumentation

Meter Loading Diagnostics

Formulas and practice problems for diagnosing DVM meter loading error, correcting true potential, estimating external resistance, and evaluating percent error.

Cathodic Protection Meter Loading Diagnostics Potential Measurement CP 3

Rectifier Calculations

These formulas cover rectifier input power, output power, efficiency, operating time, downtime, and related field calculations.

CP 3 Rectifiers Power Efficiency Downtime Instrumentation

Reference Electrode Conversions

Formulas for converting potentials between common reference electrodes and correcting readings for temperature.

CP 3 Reference Electrodes Potential Conversion Pipe-to-Soil Potentials

Reference Electrode Conversions and Temperature Corrections

Formulas for converting potentials between reference electrodes and correcting readings for temperature.

Cathodic Protection Reference Electrodes Potential Measurement CP 3

Shunt Calculations

Formulas for using shunt voltage readings and shunt ratings to determine current magnitude and related CP circuit values.

CP 3 Shunts Current Bonds Rectifiers Instrumentation

Soil Resistivity Calculations — Wenner and Barnes Methods

Formulas for calculating average soil resistivity using the Wenner method and layer resistivity using the Barnes method.

CP 3 Soil Resistivity Wenner Method Barnes Method Field Tests

Soil Resistivity Calculations — Wenner and Barnes Methods (Imperial)

Imperial formulas and practice problems for Wenner average soil resistivity and Barnes layer resistivity calculations.

CP 3 Soil Resistivity Wenner Method Barnes Method Field Tests Imperial Units

Temperature Correction and Reference Electrode Conversions

Formulas for correcting electrode potentials to 25°C and converting between common reference electrode scales.

CP 3 Reference Electrodes Temperature Correction Pipe-to-Soil Potentials