Source: https://guthlabs.ai/docs/instruments/graham-s-law-effusion-diffusion-calculator/implementation/

instrument implementation / implementation-contract

# Graham's Law Effusion/Diffusion Calculator implementation

A source-bound implementation contract for Graham's Law Effusion/Diffusion 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**: t4-171

**Effect**: Computation or source lookup only

## Input and validation requirements

The specification permits an input with zero molar mass even though it makes the square-root argument undefined, so the calculator requires explicit domain rejection. It also leaves the direction of the reported rate ratio dependent on gas labeling, creating a convention hazard.

## 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": {
    "gas1": "H2",
    "M1_g_per_mol": 2,
    "gas2": "O2",
    "M2_g_per_mol": 32,
    "known_rate1_L_per_s": 8,
    "known_time1_s": 10
  },
  "expected_outputs": {
    "rate_ratio_rate1_over_rate2": 4,
    "rate2_L_per_s": 2,
    "time2_s": 40
  },
  "working": "M2/M1 = 32/2 = 16; sqrt(16) = 4, so rate1/rate2 = 4. rate2 = rate1/4 = 8/4 = 2 L/s. For equal gas quantities, t2 = t1*sqrt(M2/M1) = 10*4 = 40 s."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/graham-s-law-effusion-diffusion-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/graham-s-law-effusion-diffusion-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/graham-s-law-effusion-diffusion-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`