CVP verified calculation capability

Test uncertainty ratio TUR Calculation Capability

Two-sided TUR = (USL−LSL)/(2U) from an already-expanded U (ANSI/NCSL Z540.3). Spec via lsl+usl, T, or half-width tol. Not pass/fail, not guard band, and not combined RSS.

Engineering · Uncertainty Capability ID engineering.uncertainty.tur version 1.0.1 CVP VERIFIED CURRENT Engineering

Model

Two-sided TUR

Two-sided TUR: TUR = (USL − LSL) / (2U)
From span: TUR = T / (2U)

Inputs / Outputs

Canonical symbols for this capability. Agent schemas remain the contract.

Symbol	Quantity	Unit	Role
`U`	Already-expanded measurement uncertainty U > 0	—	input / output
`lsl`	Lower specification limit	—	input / output
`usl`	Upper specification limit	—	input / output
`T`	Specification interval width	—	input / output
`span`	Alias for T	—	input
`tol`	Half-width; span = 2·tol	—	input / output
`TUR`	Two-sided test uncertainty ratio	—	output

Assumptions / Validity

Declared scope for this capability. Do not use it outside this domain.

Assumptions

ANSI/NCSL Z540.3 two-sided TUR = (USL−LSL)/(2U)
U is already expanded; this page does not compute U = k·u_c
tol is a half-width (span = 2·tol)
Not a pass/fail, not a guard band, and not combined RSS

Not supported

RSS of u_i
U = k·u_c as a product
guard band
Cp/Cpk
ILAC G8 pass/fail
TUR≥4 verdict boolean

Example

One numerical check. The calculator page holds worked steps and FAQ.

U=0.5 lsl=0 usl=4 → TUR=4

Open this example in the calculator

Trust

CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · ANSI/NCSL Z540.3 two-sided TUR = (USL−LSL)/(2U) for an already-expanded U, plus span T and half-width tol, + O3 mpmath tabulated TUR.. Computational verification is defined by CVP. Supplemental domain review (internal) and named expert review are defined by the Review policy and do not by themselves determine CVP conformance.

CVP: CVP VERIFIED · CVP protocol 1.0.0-proposed · Engineering assurance · ANSI/NCSL Z540.3 two-sided TUR = (USL−LSL)/(2U) for an already-expanded U, plus span T and half-width tol, + O3 mpmath tabulated TUR.· View Manifest · CVP overview · Specification
Verified scope: ANSI/NCSL Z540.3 two-sided TUR = (USL−LSL)/(2U) for an already-expanded U, plus span T and half-width tol, + O3 mpmath tabulated TUR.
Assurance: Engineering
Declared partition coverage: PASS · 5/5 declared partitions (limits, span, half-width, alias, invalid-domain)
Deferred: Not a TUR≥4 pass/fail, not a guard band, and not U = k·u_c.
Calculation version: 1.0.1
Verification: 12/12 calculation tests · 1/1 legacy golden · 7/7 legacy boundary · 4/4 legacy property
Production surface contract: 6/6
Versions: Calculation 1.0.1 · CVP protocol 1.0.0-proposed · Evidence 2026-09-23.o2-o3
Verification revision: 2026-09-23.o2-o3 · 1/1 property · digest 883bc95d518c
Reference: O1 model · O3 expected_values · O3 numerical_behavior · O2 expected_values · O2 numerical_behavior
Numerical scope: O2: ANSI/NCSL Z540.3 two-sided TUR = span/(2U) vs a separate-module identity (≤2 ULP). Not a TUR≥4 verdict, not a guard band, and not U = k·u_c. ≤2 ULP vs O3 applies only to the published tabulated Z540.3 vectors (limits, span, half-width, aliases, and one awkward span). It is not a whole-domain guarantee and does not cover a TUR≥4 verdict, a guard band, or U = k·u_c.
Interfaces: PASS · UI (SSR) / REST / MCP
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.
CVP suite: 4/4 golden · 7/7 CVP boundary · 8/8 invalid · 1/1 property · 1/1 metamorphic · 8/8 O3 · 4/4 cross-interface · 6/6 CVP contract
Supplemental domain review: Not performed
Named expert review: Not performed
Version lock: Supported (409 VERSION_MISMATCH)
Artifact consistency: Build verified · 1.0.1 (workspace artifacts agree)
Review-policy tier: Engine tested — catalog token engine_tested; supplemental; not CVP status

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

Call this capability

Human page, REST, and MCP share the same engine and calculation_version. Build verified hashes workspace artifacts only. After deploy, attest:production GETs canonical URLs twice — the public/cached view an Agent actually hits, and origin — including every /capabilities/{id} HTML page. Public Capability HTML version must match catalog before production attestation passes. Live Trust rows above fetch /.well-known/calculatorx-production-attestation.json and the output schema const. Build hashes: release integrity. That proves currently published page / engine / schema / evidence / MCP agree — not that a historical version is independently immutable. Reference Calculation Standard — Production surface contract 6/6.

curl -sS -X POST 'https://www.calculatorx.com/api/v1/calc/tur' \
  -H 'Content-Type: application/json' \
  -d '{"inputs":{"U":1,"lsl":0,"usl":5},"calculation_version":"1.0.1"}'

{
  "inputs": {
    "U": 1,
    "lsl": 0,
    "usl": 5
  },
  "calculation_version": "1.0.1"
}

POST /api/v1/calc/tur. This is a POST calculate endpoint — do not GET it.

Full REST contract: REST API docs.

Tool id: tur
Engine: tur
REST: POST /api/v1/calc/tur
MCP: execute_calculation with capability_id: "engineering.uncertainty.tur"
Agent input schema: Canonical (MCP / Agent)
Output schema: JSON Schema (latest)
Versioned input schema: Immutable pin (1.0.1)
Versioned output schema: Immutable pin (1.0.1)

References

Human-readable sources plus CVP reference evidence classes.

Sources

ANSI/NCSL Z540.3 — Requirements for the Calibration of Measuring and Test Equipment — Test uncertainty ratio (two-sided TUR = specification span / 2U)
ILAC G8:09/2019 — Guidelines on Decision Rules and Statements of Conformity — Decision rules are a different contract from TUR

Reference evidence classes: O1 model · O3 expected_values · O3 numerical_behavior · O2 expected_values · O2 numerical_behavior

Try with an agent

Inspect, then execute. Same engine as REST and the human calculator.

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: inspect_capability' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"inspect_capability","arguments":{"capability_id":"engineering.uncertainty.tur"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

curl -sS -X POST 'https://www.calculatorx.com/mcp' \
  -H 'Content-Type: application/json' \
  -H 'MCP-Protocol-Version: 2026-07-28' \
  -H 'Mcp-Method: tools/call' \
  -H 'Mcp-Name: execute_calculation' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"execute_calculation","arguments":{"capability_id":"engineering.uncertainty.tur","inputs":{"U":1,"lsl":0,"usl":5},"calculation_version":"1.0.1"},"_meta":{"io.modelcontextprotocol/protocolVersion":"2026-07-28","io.modelcontextprotocol/clientInfo":{"name":"calculatorx-docs-example","version":"1.0.0"},"io.modelcontextprotocol/clientCapabilities":{}}}}'

Pin calculation_version (1.0.1) when the result must stay reproducible.

Inspect the trust tier and required assurance level before execution. Full protocol notes: MCP docs.