Absorbance-to-Concentration (Beer-Lambert) 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

t5-157

Effect

Computation or source lookup only

Input and validation requirements

A zero extinction coefficient or zero path length produces an undefined division and must be rejected. The specification also provides no numeric validity threshold or alternate formula branch, and path-length units can cause a 100-fold concentration error if interpreted inconsistently with the extinction-coefficient units.

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": {
    "absorbance": 0.5,
    "molar_extinction_coefficient": 15000,
    "extinction_coefficient_units": "M^-1 cm^-1",
    "path_length": 1,
    "path_length_units": "cm"
  },
  "expected_outputs": {
    "concentration": 0.0000333333333333,
    "concentration_units": "M"
  },
  "working": "c = A/(ε·l) = 0.500/(15,000 × 1) = 0.500/15,000 = 0.0000333333333333 M = 3.33333333333 × 10^-5 M."
}

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-tranche5/tranche5-results.json