Source: https://guthlabs.ai/docs/instruments/steam-quality-dryness-fraction-calculator/implementation/

instrument implementation / implementation-contract

# Steam Quality (Dryness Fraction) Calculator implementation

A source-bound implementation contract for Steam Quality (Dryness Fraction) 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**: t7-023

**Effect**: Computation or source lookup only

## Input and validation requirements

The critical-point vector makes hg - hf exactly zero and the quality expression becomes 0/0. An implementation without an explicit critical-point and zero-denominator guard can produce NaN, an exception, or an invalid quality. The branch and unit vectors also expose required rejection and convention checks outside the two-phase dome.

## 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": {
    "temperature_C": 100,
    "property": "specific enthalpy",
    "h_kJ_per_kg": 419.04
  },
  "expected_outputs": {
    "quality_x": 0,
    "phase_state": "saturated liquid boundary",
    "saturation_pressure_kPa": 101.325,
    "mixture_specific_enthalpy_kJ_per_kg": 419.04
  },
  "reference_data": {
    "temperature_C": 100,
    "saturation_pressure_kPa": 101.325,
    "hf_kJ_per_kg": 419.04,
    "hg_kJ_per_kg": 2675.5,
    "source_convention": "IAPWS-IF97 standard steam-table values, rounded to the displayed precision; 100 C saturation pressure is the widely memorized standard value 101.325 kPa"
  },
  "working": "At 100 C, yf=hf=419.04 kJ/kg and yg=hg=2675.5 kJ/kg. x=(h-hf)/(hg-hf)=(419.04-419.04)/(2675.5-419.04)=0/2256.46=0.000000. Therefore x=0 and the state is saturated liquid. The saturation pressure is the table value 101.325 kPa."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/steam-quality-dryness-fraction-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/steam-quality-dryness-fraction-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/steam-quality-dryness-fraction-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-tranche7/tranche7-results.json`