Resistor Color Code Decoder/Encoder mechanism

Model scope

The core color-code lookup and resistance calculation are standard and correct for the tested 4-, 5-, and 6-band cases. Before release, define supported color-code conventions, mandatory encoder parameters, unit handling, invalid-input behavior, canonical rounding/E-series policy, and whether the product claims to encode 6-band temperature coefficients. The empty honest_label should be completed to state that reverse encoding may round or reject values and that any future camera recognition is not part of version 1.

• The stated lookup-table method is standard, but the specification does not explicitly define the digit count: 4-band uses two significant digits, while 5-band and 6-band use three significant digits.
• For 6-band codes, the sixth band is a temperature-coefficient lookup and must be reported separately; it does not change the nominal resistance.
• Reverse encoding is underspecified: the required band count, tolerance, temperature coefficient, rounding policy, and preferred representation for values not exactly representable by a valid color code are not defined.
• The implementation must reject invalid band sequences, including unsupported colors, missing tolerance bands, negative or zero resistance inputs where not explicitly supported, and noncanonical significant-digit requests.

Units and conventions

• Decoded resistance is reported in ohms unless a display-unit option is explicitly defined.
• Tolerance is expressed as percent and applies symmetrically to the nominal resistance: lower=R×(1−t/100), upper=R×(1+t/100).
• Encoder input units must be explicit; vector 4 uses kilohms and converts by 1 kΩ=1000 Ω before selecting bands.
• Temperature coefficient is expressed in ppm/K; numerically, ppm/K and ppm/°C increments are equivalent for a temperature difference.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "mode": "decode",
    "band_colors": [
      "brown",
      "black",
      "red",
      "gold"
    ]
  },
  "expected_outputs": {
    "nominal_resistance_ohms": 1000,
    "tolerance_percent": 5,
    "resistance_range_ohms": {
      "min": 950,
      "max": 1050
    }
  },
  "reference_data": {
    "digit_bands": [
      {
        "color": "brown",
        "digit": 1,
        "source_convention": "IEC 60062 / widely tabulated standard value"
      },
      {
        "color": "black",
        "digit": 0,
        "source_convention": "IEC 60062 / widely tabulated standard value"
      }
    ],
    "multiplier_band": {
      "color": "red",
      "factor": 100,
      "source_convention": "IEC 60062 / widely tabulated standard value"
    },
    "tolerance_band": {
      "color": "gold",
      "tolerance_percent": 5,
      "source_convention": "IEC 60062 / widely tabulated standard value"
    },
    "table_entry": {
      "color_code": "brown-black-red-gold",
      "meaning": "1 kΩ ±5%",
      "source_convention": "IEC 60062 / widely tabulated standard value"
    }
  },
  "working": "4-band nominal value = (brown digit 1×10 + black digit 0)×red multiplier 100 = 10×100 = 1000 Ω. Tolerance = 1000×5/100 = 50 Ω. Minimum = 1000−50 = 950 Ω. Maximum = 1000+50 = 1050 Ω."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The extreme-value encoder input lies outside the supported EIA multiplier range and must be rejected explicitly. The decoder also has a convention hazard if band direction or the metallic tolerance band is not identified, and the exact-zero code should be flagged as a zero-ohm jumper rather than treated as an ordinary resistor.

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