Source: https://guthlabs.ai/docs/instruments/sample-rate-nyquist-frequency-checker/implementation/

instrument implementation / implementation-contract

# Sample Rate / Nyquist Frequency Checker implementation

A source-bound implementation contract for Sample Rate / Nyquist Frequency Checker; 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**: 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

[01**Overview**](<https://guthlabs.ai/docs/instruments/sample-rate-nyquist-frequency-checker/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/sample-rate-nyquist-frequency-checker/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/sample-rate-nyquist-frequency-checker/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-tranche4/tranche4-results.json`