Source: https://guthlabs.ai/docs/instruments/barometric-formula-pressure-vs-altitude-general/implementation/

instrument implementation / implementation-contract

# Barometric Formula (Pressure vs Altitude, general) implementation

A source-bound implementation contract for Barometric Formula (Pressure vs Altitude, general); 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**: t5-158

**Effect**: Computation or source lookup only

## Input and validation requirements

A zero-temperature input produces division by zero in the exponent and must be rejected. The specification does not state an input-domain validation rule for T <= 0.

## 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": {
    "P0_Pa": 101325,
    "temperature_K": 288.15,
    "altitude_m": 0
  },
  "expected_outputs": {
    "P_Pa": 101325
  },
  "working": "1. Exponent = -(Mgh)/(RT) = -(0.0289644 × 9.80665 × 0)/(8.314462618 × 288.15) = 0.\n2. exp(0) = 1.\n3. P = 101325 × 1 = 101325 Pa."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/barometric-formula-pressure-vs-altitude-general/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/barometric-formula-pressure-vs-altitude-general/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/barometric-formula-pressure-vs-altitude-general/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`