Source: https://guthlabs.ai/docs/instruments/emc-emi-near-field-distance-wavelength-calculator/implementation/

instrument implementation / implementation-contract

# EMC/EMI Near-Field Distance & Wavelength Calculator implementation

A source-bound implementation contract for EMC/EMI Near-Field Distance & Wavelength Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

**Record owner**: Guth Instruments

**Lifecycle**: verified-clean

**Evidence ID**: t5-061

**Effect**: Computation or source lookup only

## Input and validation requirements

The zero-frequency vector exposes an undefined division-by-zero case that must be rejected. The unit probe also exposes a severe convention hazard: ignoring the D unit changes the Fraunhofer result by four orders of magnitude.

## Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

## Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

````
{
  "inputs": {
    "frequency_hz": 100000000,
    "D_m": 0.3
  },
  "expected_outputs": {
    "wavelength_m": 2.99792458,
    "reactive_scale_m": 0.477134516,
    "fraunhofer_boundary_m": 0.060041537
  },
  "working": "λ = c/f = 299792458 / 100000000 = 2.99792458 m. Reactive scale = λ/(2π) = 2.99792458 / 6.283185307 = 0.477134516 m. Fraunhofer boundary = 2D²/λ = 2(0.3²)/2.99792458 = 2(0.09)/2.99792458 = 0.18/2.99792458 = 0.060041537 m."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/emc-emi-near-field-distance-wavelength-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/emc-emi-near-field-distance-wavelength-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/emc-emi-near-field-distance-wavelength-calculator/qualification/>)

## Sources and evidence

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

- `VERIFIED_LEDGER.json`

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