Source: https://guthlabs.ai/docs/instruments/mach-number-calculator/implementation/

instrument implementation / implementation-contract

# Mach Number Calculator implementation

A source-bound implementation contract for Mach Number Calculator; 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**: t5-044

**Effect**: Computation or source lookup only

## Input and validation requirements

A zero-temperature input makes the speed of sound zero and the Mach-number denominator vanish; the instrument must reject it instead of exposing a JavaScript Infinity or undefined result. The altitude-based ISA calculation also requires an unstated table/branch convention at 11000 m, and signed velocity creates an explicit Mach-sign convention ambiguity.

## 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": {
    "velocity": 170.1461435,
    "velocity_unit": "m/s",
    "temperature": 288.15,
    "temperature_unit": "K",
    "gamma": 1.4,
    "R": 287.05
  },
  "expected_outputs": {
    "mach_number": 0.5,
    "speed_of_sound_m_per_s": 340.2923
  },
  "working": "a=√(γRT)=√(1.4×287.05×288.15)=√115798.8405=340.2923 m/s. M=V/a=170.1461435/340.2923=0.5000."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/mach-number-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/mach-number-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/mach-number-calculator/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-tranche5/tranche5-results.json`