Source: https://guthlabs.ai/docs/instruments/wavelength-frequency-sound-converter/

instrument / verified-clean

# Wavelength ↔ Frequency (Sound) Converter

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Status: **VERIFIED_CLEAN**Lifecycle: **verified-clean**

## Inspectable records

[01**Overview**Purpose and lifecycle](<https://guthlabs.ai/docs/instruments/wavelength-frequency-sound-converter/>)[02**Mechanism**Method and assumptions](<https://guthlabs.ai/docs/instruments/wavelength-frequency-sound-converter/mechanism/>)[03**Implementation**Binding and validation](<https://guthlabs.ai/docs/instruments/wavelength-frequency-sound-converter/implementation/>)[04**Qualification**Evidence and errata](<https://guthlabs.ai/docs/instruments/wavelength-frequency-sound-converter/qualification/>)

## Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

**Area**: Audio, Music, Photography & Color

**Tranche**: tranche-4

**Evidence ID**: t4-049

**Ledger rows**: 1

No ledger note is attached.

## Review findings

The formula is mathematically sound under the stated assumptions, but the specification needs to explicitly define both conversion directions, input-direction selection, valid ranges, and units. The empty honest_label is a concern: the instrument should disclose that this is an approximate dry-air calculation using temperature only, rather than an exact universal speed-of-sound result.

### Formula and scope findings

- The formula λ=c/f is correct for calculating wavelength from frequency when c is in m/s and f is in Hz.

- The specification claims conversion in either direction, but it does not explicitly state the inverse formula f=c/λ or define how the instrument determines which input direction to use.

- The speed formula c=331.3+0.606T is a standard linear approximation for dry air near ordinary atmospheric conditions, not a universally exact speed-of-sound formula for all air conditions.

### Unit assumptions

- Temperature T is in degrees Celsius, not Fahrenheit or Kelvin.

- Frequency is in hertz (cycles per second).

- Wavelength is in metres.

- Speed of sound is returned in metres per second.

- The inverse calculation, when wavelength is supplied, is f=c/λ.

- The approximation assumes ordinary atmospheric pressure and approximately dry air; humidity, pressure, and air composition are otherwise ignored.

## Boundary hardening

**BREAK_CLAIMED** · SELF_FLAGGED

The inverse wavelength-to-frequency operation is undefined for zero wavelength, and the specification does not state an input-domain rejection rule. A temperature-unit ambiguity can also produce materially different results if a bare value such as 68 is interpreted as Fahrenheit rather than the specified Celsius.

## Errata and corrections

No applied erratum is attached to this unique-name record.

## Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

````
{
  "inputs": {
    "frequency_hz": 440,
    "air_temperature_c": 20
  },
  "expected_outputs": {
    "speed_of_sound_m_per_s": 343.42,
    "wavelength_m": 0.7805
  },
  "working": "c = 331.3 + (0.606 × 20) = 331.3 + 12.12 = 343.42 m/s.\nλ = c/f = 343.42/440 = 0.7805 m."
}
````

## Related workflows

No source-defined multi-instrument workflow membership is recorded.

## Sources and evidence

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

- `VERIFIED_LEDGER.json · VERIFIED_CLEAN`

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

- `BOUNDARY_HAZARD_CATALOG.json`