Source: https://guthlabs.ai/docs/instruments/db-spl-dbu-dbv-converter/implementation/

instrument implementation / implementation-contract

# dB SPL / dBu / dBV Converter implementation

A source-bound implementation contract for dB SPL / dBu / dBV Converter; 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**: t2-001

**Effect**: Computation or source lookup only

## Input and validation requirements

The zero linear-ratio input produces an undefined logarithm and must be rejected. The instrument also has a convention-sensitive ratio direction and requires explicit source-scale branching to avoid confusing dBu with dBV.

## 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": {
    "source_scale": "SPL",
    "source_value_db": 94,
    "target_scale": "linear_pressure_ratio",
    "reference_pressure_Pa": 0.00002
  },
  "expected_outputs": {
    "pressure_ratio_to_p0": 50118.72336272725,
    "pressure_Pa": 1.002374467254545
  },
  "working": "SPL = 20log10(p/p0). Therefore p/p0 = 10^(94/20) = 10^4.7 = 50118.72336272725. Then p = 50118.72336272725 × 0.000020 Pa = 1.002374467254545 Pa."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/db-spl-dbu-dbv-converter/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/db-spl-dbu-dbv-converter/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/db-spl-dbu-dbv-converter/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-tranche2/tranche2-results.json`