Reciprocity Failure Calculator (Film) 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

t7-030

Effect

Computation or source lookup only

Input and validation requirements

The calculator must reject negative metered times when using a fractional exponent such as 1.3 because the real-valued result is undefined. It also has a significant unit-convention hazard: applying the power to an unnormalized numeric time makes seconds and minutes produce different physical results.

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": {
    "metered_time": 1,
    "time_unit": "s",
    "exponent_p": 1.3,
    "film_stock": "manual exponent"
  },
  "expected_outputs": {
    "corrected_time_s": 1
  },
  "reference_data": {
    "time_reference_s": 1,
    "source_convention": "widely tabulated standard value (SI): one second equals one second",
    "exponent_p": 1.3,
    "source_convention_exponent": "user-supplied manual exponent; not a manufacturer table value"
  },
  "working": "correctedTime = meteredTime^p\n= 1^1.3\n= 1 s.\nThis is an exact boundary case and lands on the widely memorized 1-second SI time entry."
}

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