Cylindrical/Spherical Conduction Resistance Calculator implementation

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

t4-120

Effect

Computation or source lookup only

Input and validation requirements

The specified formulas expose unhandled invalid-input hazards: equal radii produce zero resistance and an undefined heat-rate division, zero conductivity produces a division-by-zero resistance, and an unstated sign convention can reverse the heat-rate sign.

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": {
    "geometry": "cyl",
    "r1_m": 0.05,
    "r2_m": 0.06,
    "k_W_per_mK": 0.5,
    "L_m": 1,
    "deltaT_K": 100
  },
  "expected_outputs": {
    "R_total_K_per_W": 0.0580348,
    "q_W": 1723.1054
  },
  "working": "R=ln(0.06/0.05)/(2π·0.5·1)=ln(1.2)/π=0.1823215568/3.141592654=0.0580348 K/W. q=ΔT/R=100/0.0580348=1723.1054 W."
}

Other records

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