Wavelength ↔ Frequency (Sound) Converter

Inspectable records

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