Wire Gauge (AWG/SWG) ↔ Diameter/Area Converter mechanism

Model scope

The AWG diameter equation is valid, and the area and resistance arithmetic above is consistent with the stated assumptions. Verdict is NEEDS_REVIEW because SWG data/algorithm, diameter-standard selection, conductor material, resistivity convention, temperature, valid ranges, and rounding behavior are not specified. The honest label should say that resistance is nominal conductor resistance at a stated temperature and material, not guaranteed installed-cable resistance.

• The AWG diameter formula is correct for nominal American Wire Gauge: d(mm)=0.127×92^((36−AWG)/39).
• Cross-sectional area is not stated but must be computed as A=πd²/4.
• Resistance requires R=ρL/A, with diameter converted from mm to m before calculating SI resistance.
• No SWG conversion algorithm or SWG table is supplied, although SWG is an advertised input/output standard. AWG and SWG numbers are not interchangeable.
• Diameter-to-gauge conversion is underspecified: the instrument must identify whether the diameter is being interpreted as AWG or SWG, and should define rounding and valid gauge ranges.
• Resistance cannot be determined from gauge alone without conductor material, resistivity convention, and temperature. If the instrument claims copper resistance, that must be stated explicitly.

Units and conventions

• AWG diameters are nominal bare-conductor diameters in millimetres, using the standard 0.127 mm AWG-36 reference diameter.
• Area is reported in mm².
• Resistivity values are assumed to be at 20 °C; resistance uses R=ρL/A.
• For resistance calculations, area in mm² is converted to m² by multiplying by 10^-6.
• Ω/km uses L=1000 m; Ω/1000 ft uses the exact conversion 1000 ft=304.8 m.
• The test vectors explicitly assume annealed copper with ρ=1.68×10^-8 Ω·m, a widely tabulated standard value at 20 °C.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "standard": "AWG",
    "gauge": 36,
    "material": "annealed copper",
    "temperature_C": 20,
    "requested_resistance_lengths": [
      "1 km",
      "1000 ft"
    ]
  },
  "expected_outputs": {
    "diameter_mm": 0.127,
    "area_mm2": 0.012667687,
    "resistance_ohm_per_km": 1326.21,
    "resistance_ohm_per_1000ft": 404.23
  },
  "reference_data": {
    "awg_row": {
      "gauge": 36,
      "diameter_mm": 0.127,
      "source_convention": "AWG standard, widely tabulated standard value"
    },
    "copper_resistivity_ohm_m_20C": 1.68e-8,
    "source_convention_resistivity": "widely tabulated standard value for copper at 20 °C",
    "pi": 3.141592653589793,
    "source_convention_pi": "mathematical constant",
    "metres_per_1000ft": 304.8,
    "source_convention_length": "exact SI/international-foot conversion"
  },
  "working": "d=0.127 mm (the exact AWG-36 table entry). A=πd²/4=3.141592653589793×(0.127²)/4=3.141592653589793×0.016129/4=0.012667687 mm². Convert area: A=0.012667687×10^-6=1.2667687×10^-8 m². R/km=ρL/A=(1.68×10^-8 Ω·m×1000 m)/(1.2667687×10^-8 m²)=1326.21 Ω/km. R/1000 ft=(1.68×10^-8×304.8)/(1.2667687×10^-8)=404.23 Ω/1000 ft."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The specification does not define rejection behavior for zero diameter, does not identify the exact valid AWG range, and does not require an explicit AWG-versus-SWG selector or diameter unit. These omissions permit undefined outputs and materially different numeric results.

Other records

Sources and evidence

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

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json
• BOUNDARY_HAZARD_CATALOG.json