Source: https://guthlabs.ai/docs/instruments/stirling-cycle-efficiency-calculator/implementation/

instrument implementation / implementation-contract

# Stirling Cycle Efficiency Calculator implementation

A source-bound implementation contract for Stirling Cycle Efficiency Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## 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**: t4-036

**Effect**: Computation or source lookup only

## Input and validation requirements

The calculator must reject V1=0 because the volume ratio divides by zero and the logarithm is undefined. It also needs explicit unit handling for absolute temperature; interpreting Celsius values as kelvin gives a wrong efficiency.

## 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": {
    "Th": 600,
    "Tc": 300,
    "V1": 1,
    "V2": 2,
    "n": 1,
    "temperature_unit": "K",
    "volume_unit": "L"
  },
  "expected_outputs": {
    "η": 0.5,
    "net_work_per_cycle_J": 1728.85
  },
  "working": "η=1−Tc/Th=1−300/600=1−0.5=0.5. Wnet=nR(Th−Tc)ln(V2/V1)=1×8.314×(600−300)×ln(2/1)=8.314×300×0.693147=2494.2×0.693147=1728.85 J/cycle."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/stirling-cycle-efficiency-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/stirling-cycle-efficiency-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/stirling-cycle-efficiency-calculator/qualification/>)

## Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

- `VERIFIED_LEDGER.json`

- `evidence-tranche4/tranche4-results.json`