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 1.0.0

Open calculator REST API MCP Evidence Evidence JSON Review policy

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. Provide with usl, or use T or tol instead.	—	input / output
`usl`	Upper specification limit. Must be greater than lsl.	—	input / output
`T`	Specification interval width (span). Alias: span. Do not combine with lsl+usl or tol.	—	input / output
`span`	Alias for T.	—	input
`tol`	Half-width; span = 2·tol. Do not combine with lsl+usl or T.	—	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

Review-policy: engine tested — automated tests, sources, version lock, and evidence published. Supplemental to CVP; not Domain Expert Review. See CVP and Review policy.

Tier: Engine tested — catalog token engine_tested
Calculation version: 1.0.0
Evidence tests: 11/11 calculation tests · golden 0/0 · boundary 7/7 · property 4/4
Engine tested: Yes
Source checked: Yes
Supplemental domain review: Not performed
Named expert review: Not performed
Version lock: Supported (409 VERSION_MISMATCH)
Artifact consistency: Build verified · 1.0.0 (workspace artifacts agree)

Production attestation: Embedded snapshot: STALE · Last attested schema matched 1.0.0 snapshot / local build · Semantic contract ✓ · Last attestation PASS · current evidence changed · re-attestation required · Public/cache ✓ · Origin ✓ · Live production status PASS (0 stale; 164 CURRENT) @ 2026-09-16T06:44:24.909Z
Semantic contract: PASS
Evidence attested at: 2026-09-16T06:44:24.203Z
Last production check: 2026-09-16T06:44:24.203Z
Public / cache: PASS
Origin: PASS

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 4/4.

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 (1.0.0)
Versioned output schema: Immutable pin (1.0.0)

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

Try with an agent

Inspect this capability via same-origin MCP, then call execute_calculation.

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"}}}'

Inspect the trust tier and required assurance level before execution. Pin calculation_version (1.0.0) when reproducibility matters. Full protocol notes: MCP docs.