FieldengCathodic Protection
Barnes Layer Resistivity
Resistivity of one depth interval from two successive Wenner measurements.
Cathodic Protection
Resistivity of one depth interval from two successive Wenner measurements.
App id: SOIL-07. 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
ΔS = S2 − S1; R_layer = R1 R2 / (R1 − R2); ρ_layer = 2π ΔS R_layerInputs
| Name | Unit |
|---|---|
| Previous spacing | ft |
| Previous resistance | ohm |
| Current spacing | ft |
| Current resistance (camera) | ohm |
Outputs
| Name | Unit |
|---|---|
| Layer thickness | ft |
| Layer resistance | ohm |
| Layer resistivity (hero result) | ohm-cm |
Diagnose
Observations are context. They do not pass or fail a structure. See Diagnose.
Screening bands in the app: Very Low · Low · Moderate · High · Very High.
| When | Observation | Severity |
|---|---|---|
resistivity < 1,000 Ω·cm | Very Low | info |
1,000 ≤ resistivity < 3,000 Ω·cm | Low | info |
3,000 ≤ resistivity < 10,000 Ω·cm | Moderate | info |
10,000 ≤ resistivity < 30,000 Ω·cm | High | info |
resistivity ≥ 30,000 Ω·cm | Very High | info |
Assumptions
- Single interval extracted from the Barnes successive-layer method.
- Throws if adjacent measured resistances are equal or nearly equal.
Provenance
- NACE/CP2 training material describing Barnes Layer calculations.