Sample Rate / Nyquist Frequency Checker implementation

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

t4-001

Effect

Computation or source lookup only

Input and validation requirements

• A zero or negative sample rate is invalid and must be rejected; zero yields a mathematically defined result but no usable sampling capability.
• The implementation must avoid implying that a frequency exactly equal to fs/2 is generally safe to represent; use a boundary-aware label such as Nyquist limit or require frequency < fs/2.
• The aliasing claim is incomplete without a signal-frequency input and a comparison rule.
• Unit omission can cause a 1000-fold error, such as interpreting 44.1 kHz as 44.1 Hz.
• The common-rate table should explicitly state units and whether values are displayed in Hz or kHz.

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": {
    "sample_rate": 44100,
    "sample_rate_unit": "Hz"
  },
  "expected_outputs": {
    "nyquist_frequency": 22050,
    "nyquist_frequency_unit": "Hz"
  },
  "working": "fmax = fs / 2 = 44100 Hz / 2 = 22050 Hz."
}

Other records

Sources and evidence

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

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json