Source: https://guthlabs.ai/docs/instruments/ground-loop-common-impedance-voltage-estimator/

instrument / verified-clean

# Ground Loop / Common-Impedance Voltage Estimator

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/ground-loop-common-impedance-voltage-estimator/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/ground-loop-common-impedance-voltage-estimator/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/ground-loop-common-impedance-voltage-estimator/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/ground-loop-common-impedance-voltage-estimator/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Electrical & Electronics Engineering — Circuits, Power Systems, Electronics Lab

**Tranche**: tranche-5

**Evidence ID**: t5-071

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The R+jωL model is standard for a simplified series shared-conductor impedance, and the supplied honest label appropriately identifies it as a lumped approximation. Verdict remains NEEDS_REVIEW because amplitude convention, phasor/sinusoidal scope, and the explicit magnitude formula are not fully specified.

### Formula and scope findings

- The stated formula Vnoise=I×Zground is a complex voltage relation, but the declared output is voltage magnitude; the implemented magnitude should be Vnoise=|I|×sqrt(R^2+(2πfL)^2) for a sinusoidal phasor current.

- The specification does not state whether current and voltage amplitudes are RMS, peak, or instantaneous values; the same convention must be used consistently.

- A single frequency and lumped R+jωL model is not sufficient for arbitrary or non-sinusoidal return currents without specifying that the calculation applies to one sinusoidal frequency component.

### Unit assumptions

- Frequency is supplied in hertz and converted with ω=2πf in radians per second.

- Resistance R is in ohms, inductance L is in henries, current I is in amperes, and output voltage is in volts.

- The test vectors use RMS current, so the reported noise voltage is RMS magnitude.

- R and L are assumed nonnegative real parameters, and the shared conductor is modeled as a series impedance.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

The extreme-magnitude vector produces 1e616 V mathematically, which overflows standard JavaScript Number arithmetic to Infinity. The instrument should reject or explicitly flag overflow rather than return Infinity without warning.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "return_current_A_rms": 4,
    "ground_resistance_ohm": 0.25,
    "ground_inductance_H": 0.002387324,
    "frequency_Hz": 50
  },
  "expected_outputs": {
    "noise_voltage_magnitude_V_rms": 3.1623
  },
  "working": "ω=2πf=2×3.14159265×50=314.159265 rad/s. X_L=ωL=314.159265×0.002387324≈0.750000 Ω. |Z|=sqrt(R²+X_L²)=sqrt(0.25²+0.75²)=sqrt(0.0625+0.5625)=sqrt(0.625)=0.790569 Ω. Vnoise=I|Z|=4×0.790569=3.162277 V≈3.1623 V RMS."
}
````

## Related workflows

No source-defined multi-instrument workflow membership is recorded.

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

- `evidence-tranche5/tranche5-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`