Source: https://guthlabs.ai/docs/instruments/unit-converter-physics-quantities/

instrument / verified-clean

# Unit Converter — Physics Quantities

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

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/unit-converter-physics-quantities/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/unit-converter-physics-quantities/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/unit-converter-physics-quantities/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/unit-converter-physics-quantities/qualification/>)

## Ledger state

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

**Area**: Physics — Kinematics/Projectiles/Orbits, Forces/Energy/Momentum, Rotational Dynamics, Gravitation, Oscillations/Waves, Optics, E&M Fields, Relativity, Quantum, Statistical Thermo

**Tranche**: tranche-6

**Evidence ID**: t6-138

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The stated algorithm is standard for compatible, multiplicative physics units, but the specification is not sufficiently precise to certify the instrument. Supply a versioned factor table, define all unit conventions and significant-digit/rounding behavior, and specify rejection behavior for incompatible, offset, and logarithmic units.

### Formula and scope findings

- Linear scale-factor multiplication is correct for conversions between compatible linear units, but the specification does not provide the actual conversion-factor table needed for verification.

- The converter must enforce dimensional compatibility; converting between incompatible quantity types must be rejected rather than applying an arbitrary factor.

- The specification does not define conventions for ambiguous units such as calorie, light-year, parsec, and amu, nor the precision and rounding policy for returned values.

- A purely linear model does not cover offset units such as degrees Celsius/Fahrenheit or logarithmic units such as decibels; these must be explicitly excluded or handled separately.

### Unit assumptions

- eV uses the exact SI elementary-charge relation: 1 eV = 1.602176634e-19 J.

- 1 J = 1e7 erg exactly by the SI-to-cgs definition.

- 1 AU = 149597870700 m exactly (IAU nominal astronomical unit).

- 1 pc = (648000/pi) AU, using the IAU parsec definition and pi = 3.141592653589793.

- The zero-calorie test is independent of the calorie convention; nonzero calorie conversions require an explicit choice such as thermochemical calorie, 1 cal_th = 4.184 J.

- The amu, if supported, should mean the unified atomic mass unit (dalton), not an alternative historical atomic-mass convention.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

An extreme but representable input value, 1e308 J, converts mathematically to approximately 6.241509074460763e326 eV and overflows a JavaScript IEEE-754 Number to Infinity. The calorie probe also exposes a convention-dependent result if the lookup table does not specify the calorie definition.

## 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": {
    "quantity_type": "energy",
    "value": 0,
    "from_unit": "cal",
    "to_unit": "J",
    "calorie_convention": "thermochemical"
  },
  "expected_outputs": {
    "value": 0,
    "unit": "J"
  },
  "working": "1. Apply the linear conversion: J = cal × 4.184 J/cal. 2. J = 0 × 4.184 = 0 J. This is an edge case and gives the same result for any calorie convention."
}
````

## 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-tranche6/tranche6-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`