Source: https://guthlabs.ai/docs/instruments/dew-point-calculator/implementation/

instrument implementation / implementation-contract

# Dew Point Calculator implementation

A source-bound implementation contract for Dew Point 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**: t4-289

**Effect**: Computation or source lookup only

## Input and validation requirements

RH=0 produces an undefined logarithm and must be rejected. The specification does not state validation behavior for this input. It also does not define comfort-category thresholds or explicitly state the temperature-unit convention, creating additional implementation hazards.

## 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": {
    "temperature_C": 20,
    "relative_humidity_percent": 50
  },
  "expected_outputs": {
    "dew_point_C": 9.254,
    "dew_point_F": 48.657
  },
  "working": "alpha=ln(50/100)+(17.27*20)/(237.7+20)=ln(0.5)+345.4/257.7=-0.693147+1.340318=0.647171. Td=(237.7*0.647171)/(17.27-0.647171)=153.8325/16.622829=9.254 °C. Fahrenheit=9.254*9/5+32=16.657+32=48.657 °F."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/dew-point-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/dew-point-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/dew-point-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-tranche4/tranche4-results.json`