Source: https://guthlabs.ai/docs/instruments/steam-table-property-lookup/implementation/

instrument implementation / implementation-contract

# Steam Table Property Lookup implementation

A source-bound implementation contract for Steam Table Property Lookup; 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**: t7-033

**Effect**: Computation or source lookup only

## Input and validation requirements

The specification exposes two hard hazards: P=0 produces an undefined result and must be rejected, while the permitted P/T input does not define pressure units, absolute-versus-gauge convention, or quality at saturation. Consequently the same displayed input can select different regions or fail to determine unique h, s, v, u, and cp values.

## 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": {
    "pressure_kPa": 101.325,
    "temperature_C": 100,
    "quality": 0,
    "state_specification": "saturated liquid"
  },
  "expected_outputs": {
    "h_kJ_per_kg": 419.04,
    "s_kJ_per_kg_K": 1.3072,
    "v_m3_per_kg": 0.001043,
    "u_kJ_per_kg": 418.9343,
    "cp_kJ_per_kg_K": 4.216,
    "phase_region": "saturation boundary, saturated liquid"
  },
  "reference_data": {
    "pressure_kPa": {
      "value": 101.325,
      "source_convention": "widely tabulated standard value; water saturation pressure at 100 C"
    },
    "temperature_C": {
      "value": 100,
      "source_convention": "widely tabulated standard value; normal boiling point of water at 101.325 kPa"
    },
    "hf_kJ_per_kg": {
      "value": 419.04,
      "source_convention": "IAPWS/IF97 standard steam-table value"
    },
    "sf_kJ_per_kg_K": {
      "value": 1.3072,
      "source_convention": "IAPWS/IF97 standard steam-table value"
    },
    "vf_m3_per_kg": {
      "value": 0.001043,
      "source_convention": "IAPWS/IF97 standard steam-table value"
    },
    "cp_liquid_kJ_per_kg_K": {
      "value": 4.216,
      "source_convention": "widely tabulated standard value near 100 C"
    }
  },
  "working": "At 100 C and 101.325 kPa, x=0 selects saturated liquid. h = hf = 419.04 kJ/kg. s = sf = 1.3072 kJ/(kg K). v = vf = 0.001043 m^3/kg. u = h - Pv = 419.04 - (101.325)(0.001043) = 419.04 - 0.105682 = 418.9343 kJ/kg. cp is reported from the liquid-property table as 4.216 kJ/(kg K). This is an exact normal-boiling-point table entry and an edge case at x=0."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/steam-table-property-lookup/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/steam-table-property-lookup/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/steam-table-property-lookup/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`