Public evidence

electrical.rf.coax

Machine-checked verification for calculation version 1.0.1 · tier internally_reviewed

Open calculator API Capability Download JSON CVP Manifest MCP Review policy

CVP: CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance· Ideal TEM coax; homogeneous, lossless, non-magnetic dielectric (μr≈1); conductor loss and dielectric dispersion neglected. Omitted εr defaults to 1.0. · Protocol · Schema · Production report

Declared partition coverage: PASS · 2/2 declared partitions (z0, invalid-domain)
Versions: Calculation 1.0.1 · CVP protocol 1.0.0-proposed
CVP identity: 5/5 property · digest eb5f53204f54

Verification

Legacy regression suite: 21/21 calculation tests · Production surface contract 4/4

Three distinct suites: educational examples on the calculator page, this legacy regression count (21/21 golden + boundary), and the CVP verification suite below. They are not the same number. Property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the CVP Manifest . SKIP (0/0) means that suite has no published vectors.

This calculator CURRENT · Public schema 1.0.1 matches · Semantic contract ✓ · Production attested · Public/cache ✓ · Origin ✓

CVP verification suite

Protocol checks from the Evidence Manifest. Distinct from the legacy regression suite above. Calculation version 1.0.1. CVP 1.0.0-proposed. 1/1 golden · 9/9 CVP boundary · 18/18 invalid · 5/5 property · 2/2 metamorphic · 3/3 cross-interface · 4/4 CVP contract. digest eb5f53204f54.

Golden (oracle-backed) 1 / 1
CVP boundary 9 / 9
Invalid input 18 / 18
Property 5 / 5
Metamorphic 2 / 2
Cross-interface 3 / 3
CVP contract 4 / 4
Interfaces PASS · UI (SSR) / REST / MCP
Interface claim ui-ssr is query-result HTML, not a live browser session. Error-path engine·REST·MCP 1/1 (status, code, calculation_version). SSR compared on URL-canonical requested calculations; empty query is idle (not an error) and JSON-typed object/array inputs are REST/MCP-only.
Assurance Engineering

release artifacts aligned PASS
schema valid input executes PASS
engine success output validates schema PASS
schema rejects incomplete input PASS

Fingerprint sha256:ce06ee92346ecfb20b7e53849a9e35d64f76c0e3e3b0681c6c7991e592ce187e

Input schema sha256:238096127bce9b927422b6f723d34b14a1361ca5931027a5ca9c3d366706b204 · Output schema sha256:8402a00ce0ce19cd0a0fd73b6cc066e2d8b452a2340ac3a5ab8bd1c443b561d0 · Build-time SHA-256 digests prove published artifacts agree with each other (release_integrity.scope=workspace). Production attestation GETs canonical URLs twice (public/cached view and origin), including Capability HTML, via npm run attest:production --write (published at /.well-known/calculatorx-production-attestation.json) and fails if the public Capability page advertises a different calculation_version. This is artifact consistency, not an independent immutable release log.

Build & scope

Engine identity and declared limitations.

Tool: coax-impedance
Engine: coax-impedance
Engine build: 2026-09-12
Evidence core: 2026-09-12T13:22:04.137Z
Rendered: 2026-09-16T22:03:43.750Z
Last reviewed: 2026-09-12

Assumptions

Ideal TEM coaxial transmission line
Homogeneous dielectric
Lossless / low-loss approximation
Non-magnetic dielectric, μr ≈ 1
Omitted εr defaults to 1.0 (air/vacuum approximation)

Limitations

Does not model conductor loss
Does not model dielectric loss / tanδ
Does not model dispersion
Does not model connectors or discontinuities
Does not model higher-order modes

Sources

Standards and references supporting this tool specification. Methods are listed separately — they are algorithms, not bibliographic sources.

David M. Pozar, Microwave Engineering — 4th ed., Ch. 2 Transmission Line Theory — coaxial line · 2012
Supports: Ideal TEM coax Z0 = (η0/(2π√εr)) ln(D/d) with μr≈1
Robert E. Collin, Foundations for Microwave Engineering — 2nd ed., coaxial transmission line · 2001
Supports: Z0 ∝ ln(D/d)/√εr for homogeneous non-magnetic dielectric

Legacy published checks

Golden and boundary cases from the legacy Evidence JSON. CVP property, metamorphic, round-trip, O3, and interface statuses/checks are recorded in the Manifest — including SKIP when a suite has no vectors.

ID	Kind	Status	Detail
`z0`	golden	pass	Expected Z0_ohm=56.64342736256609 · Actual mode=z0 · D_m=0.0066 · d_m=0.0016 · er=2.25 · VF=0.6666666666666666 · Z0_ohm=56.64342736256609 · ratio_D_d=4.125
`preset-50ohm-pe`	golden	pass	Expected Z0_ohm=50 · Actual mode=z0 · D_m=0.005589383451829196 · d_m=0.0016 · er=2.25 · VF=0.6666666666666666 · Z0_ohm=49.99999999999999 · ratio_D_d=3.4933646573932475
`preset-75ohm-pe`	golden	pass	Expected Z0_ohm=75 · Actual mode=z0 · D_m=0.010446862193318057 · d_m=0.0016 · er=2.25 · VF=0.6666666666666666 · Z0_ohm=75 · ratio_D_d=6.529288870823786
`er-default`	golden	pass	Expected er=1 · Z0_ohm=84.96514104384914 · Actual mode=z0 · D_m=0.0066 · d_m=0.0016 · er=1 · VF=1 · Z0_ohm=84.96514104384914 · ratio_D_d=4.125
`bad`	boundary	pass	Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE
`boundary-coax-eq`	boundary	pass	Expected VALUE_OUT_OF_RANGE · Actual VALUE_OUT_OF_RANGE
`boundary-coax-D-zero`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-coax-d-zero`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-coax-D-neg`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-coax-d-neg`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-coax-er-zero`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`boundary-coax-er-neg`	boundary	pass	Expected VALUE_MUST_BE_POSITIVE · Actual VALUE_MUST_BE_POSITIVE
`property-coax-scale`	property	pass	Z0(kD,kd)=Z0(D,d)
`property-coax-er-scale`	property	pass	εr×4 → Z0/2
`property-coax-mono-D`	property	pass	D↑ → Z0↑
`property-coax-mono-d`	property	pass	d↑ → Z0↓
`property-coax-vf`	property	pass	VF·√εr=1
`property-coax-preset-50`	property	pass	50 Ω PE preset
`property-coax-preset-75`	property	pass	75 Ω PE preset
`property-coax-er-default`	property	pass	omitted εr → 1.0
`property-coax-ln`	property	pass	η0/2π at ln(D/d)=1