Source: https://guthlabs.ai/docs/instruments/absorption-reflection-coefficient-lookup-acoustic-materials/implementation/

instrument implementation / implementation-contract

# Absorption/Reflection Coefficient Lookup (Acoustic Materials) implementation

A source-bound implementation contract for Absorption/Reflection Coefficient Lookup (Acoustic Materials); 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**: t7-091

**Effect**: Computation or source lookup only

## Input and validation requirements

The specification supplies no actual published data table, so coefficient values cannot be independently verified from the instrument specification. The lookup also has exposed hazards at unsupported or extreme frequency inputs and at ambiguous unit/convention text unless validation and explicit unit normalization are implemented.

## 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": {
    "material": "ideal rigid wall",
    "frequency_band_hz": 1000
  },
  "expected_outputs": {
    "absorption_coefficient_alpha": 0
  },
  "reference_data": {
    "material": "ideal rigid wall",
    "frequency_band_hz": 1000,
    "absorption_coefficient_alpha": 0,
    "source_convention": "widely tabulated standard value; ideal perfectly reflective boundary reference, octave-band convention"
  },
  "working": "1. Match the material key: ideal rigid wall. 2. Match the exact octave-band key: 1000 Hz. 3. Retrieve α = 0.00. 4. No interpolation or unit conversion is performed. This is the canonical zero-absorption reference entry."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/absorption-reflection-coefficient-lookup-acoustic-materials/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/absorption-reflection-coefficient-lookup-acoustic-materials/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/absorption-reflection-coefficient-lookup-acoustic-materials/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`