Blood Alcohol Concentration (Widmark estimate) implementation

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

t4-182

Effect

Computation or source lookup only

Input and validation requirements

The specification does not define beta, does not state whether the formula's BAC is a fraction or percentage, does not define standard-drink gram content, and permits a negative raw BAC at the zero-alcohol boundary. It also has an undefined result at zero body weight.

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": {
    "alcohol_g": 56,
    "weight_g": 80000,
    "sex": "M",
    "r": 0.68,
    "elapsed_hours": 2,
    "beta_percent_points_per_hour": 0.015
  },
  "expected_outputs": {
    "raw_formula_BAC_percent": 0.07294117647,
    "estimated_BAC_percent": 0.07294117647,
    "time_to_sober_hours": 4.8627451
  },
  "working": "Denominator = 80000 × 0.68 = 54400 g. Widmark fraction = 56 ÷ 54400 = 0.0010294117647. Convert to percent: 0.0010294117647 × 100 = 0.10294117647%. Metabolism = 0.015 × 2 = 0.03 percentage points. Estimated BAC = 0.10294117647 − 0.03 = 0.07294117647%. Time to sober = 0.07294117647 ÷ 0.015 = 4.8627451 hours."
}

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-tranche4/tranche4-results.json