Source: https://guthlabs.ai/docs/instruments/carnot-efficiency-calculator/

instrument / verified-clean

# Carnot Efficiency Calculator

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/carnot-efficiency-calculator/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/carnot-efficiency-calculator/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/carnot-efficiency-calculator/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/carnot-efficiency-calculator/qualification/>)

## Ledger state

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

**Area**: Thermodynamics, Fluids & Aero

**Tranche**: tranche-2

**Evidence ID**: t2-036

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The honest label is appropriate: this is a reversible Carnot upper bound, not an achievable efficiency for real engines. Verdict is NEEDS_REVIEW because the input temperature units and the ratio-to-percent conversion are not explicitly specified, and the required Th>Tc≥0 K constraint is omitted.

### Formula and scope findings

- The Carnot efficiency formula η=1−Tc/Th is correct for a reversible heat engine when Tc and Th are absolute temperatures and Th>Tc.

- The formula returns a dimensionless ratio; the stated percentage output requires an explicit conversion η_percent=100×(1−Tc/Th).

- The specification does not explicitly state the required validity constraint Th>Tc≥0 K. Inputs with Th≤Tc are invalid for the claimed heat-engine calculation.

### Unit assumptions

- Th and Tc must be absolute temperatures in kelvins, or another absolute scale with the same ratio behavior.

- If users enter Celsius or Fahrenheit, values must be converted to kelvins before applying the formula: T(K)=T(°C)+273.15 and T(K)=(T(°F)+459.67)×5/9.

- η is dimensionless; η (%) is the dimensionless result multiplied by 100.

- Maximum work per unit heat input is W_max/Q_in=η, so for 1 unit of heat input the maximum work is η units.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

The specification exposes a division-by-zero input at Th=0 and a physically invalid reversed-temperature ordering that produces a negative raw efficiency. A robust calculator must reject both rather than display misleading numeric results.

## 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": {
    "Th": 600,
    "Tc": 300,
    "temperature_unit": "K"
  },
  "expected_outputs": {
    "eta_ratio": 0.5,
    "eta_percent": 50,
    "max_work_per_unit_heat": 0.5
  },
  "working": "η=1−Tc/Th=1−300/600=1−0.5=0.5. η_percent=100×0.5=50%. For 1 unit of heat input, W_max/Q_in=0.5, so W_max=0.5 unit."
}
````

## Related workflows

[Engine Cycle Comparatorupper bound](<https://guthlabs.ai/docs/instrument-workflows/engine-cycles/>)

## 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-tranche2/tranche2-results.json`

- `BOUNDARY_HAZARD_CATALOG.json`