FieldengCathodic Protection
CP Polarization Shift
Signed and absolute shift between native and polarized pipe-to-soil potentials.
Cathodic Protection
Signed and absolute shift between native and polarized pipe-to-soil potentials.
App id: MEAS-04. Reference version 1.0.
How to fill it
Fill the inputs. The tool shows the outputs.
On the tool screen, Calc is the working sheet. Presets stores values you reuse. Reference is the formula, assumptions, and provenance below.
Formula
ΔV = Vpolarized − VnativeInputs
| Name | Unit |
|---|---|
| Native potential (camera) | mV |
| Polarized potential (camera) | mV |
Outputs
| Name | Unit |
|---|---|
| Shift magnitude (hero result) | mV |
| Signed shift (polarized − native) | mV |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
| When | Observation | Severity |
|---|---|---|
Signed shift (polarized − native) > 1e-6 | Anomalous polarity | warning |
|Signed shift (polarized − native)| < 0.01 | Little or no cathodic shift | caution |
|Signed shift (polarized − native)| ≥ 0.1 | Cathodic shift ≥ 100 mV | info |
|Signed shift (polarized − native)| < 0.1 | Cathodic shift below 100 mV | caution |
Assumptions
- Cathodic polarization makes the polarized reading more negative than native, so the signed shift is negative.
Provenance
- A 100 mV polarization shift appears in some CP criteria as engineering context, not a compliance verdict.