Alcohol Unit / Standard Drink Counter

Inspectable records

Ledger state

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

Area

Biology, Medicine & Pharmacology (educational estimates only — every panel labeled not-medical-advice)

Tranche

tranche-5

Evidence ID

t5-057

Ledger rows

1

No ledger note is attached.

Review findings

The UK arithmetic formula is sound under the stated unit assumptions. The specification is not complete for US standard drinks or weekly guideline comparisons because the US conversion formula, ethanol-density assumption, jurisdiction, threshold, and accumulation period are missing.

Formula and scope findings

• The UK formula is correct when Volume is in mL and ABV% is expressed as a numeric percentage: UK units = Volume_mL × ABV% ÷ 1000.
• The US formula is incomplete: 14 g is the definition of one US standard drink, but the specification does not provide the conversion from beverage volume and ABV to grams of ethanol. A density assumption is required, such as ethanol density = 0.789 g/mL.
• UK units and US standard drinks are different measures and must not be presented as interchangeable.
• The claimed weekly total requires a time period, accumulated consumption inputs, country or jurisdiction, and a specified guideline threshold. None is defined.
• The input field 'volume' is ambiguous unless its unit is explicitly constrained to mL or converted before calculation.
• ABV% is ambiguous unless the interface requires percentage points such as 5, rather than a fractional value such as 0.05.

Unit assumptions

• Volume is entered in millilitres.
• ABV% is entered as a numeric percentage: 5 means 5% ABV; internally it is divided by 100.
• UK units are calculated as millilitres of pure ethanol divided by 1000.
• US standard drinks use 14 g of pure ethanol per drink.
• The test-vector US conversions assume ethanol density of 0.789 g/mL: pure_ethanol_g = pure_ethanol_mL × 0.789.
• The weekly guideline cannot be evaluated without a specified country, guideline source, time period, and threshold.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The extreme-magnitude vector produces Infinity through JavaScript floating-point overflow, and the US branch is not uniquely computable from the supplied formula without an ethanol-density assumption. ABV notation also permits a factor-100 convention error unless the input representation is explicit.

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": {
    "volume_ml": 500,
    "abv_percent": 5,
    "unit_system": "UK and US"
  },
  "expected_outputs": {
    "uk_units": 2.5,
    "us_standard_drinks": 1.4089285714,
    "pure_alcohol_ml": 25,
    "pure_alcohol_g": 19.725
  },
  "working": "Pure alcohol = 500 × 5 ÷ 100 = 25 mL. UK units = 25 ÷ 1000 = 2.5. Pure alcohol mass = 25 × 0.789 = 19.725 g. US standard drinks = 19.725 ÷ 14 = 1.4089285714."
}

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