22-EFT.WP.Metrology.Instrument v1.0 | Preface

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Preface

I. Purpose and Applicable Scenarios

• Unify instrumentation metrology, calibration, and uncertainty publication across benchtop, embedded, and in-service contexts, enabling an end-to-end loop for R&D, production testing, and operational monitoring.
• Standardize measurement functions, uncertainty budgets, and certificate issuance; coordinate with the TimeBase, Sync, Cleaning, and Imaging volumes to deliver a complete, auditable chain from front-end acquisition to certified release.
• Target engineering deliveries that must be traceable, reproducible, and auditable: type evaluation, production release, in-service comparisons, cross-site harmonization, and templated compliance.

II. Audience and Reading Paths

1. Intended readers: metrology/test engineers, lab managers, data & algorithm engineers, and quality & compliance leads.
2. Suggested reading paths:
   • Chapter 2 (Modeling Baseline) → Chapter 4 (Range & Dynamic Range) → Chapter 6 (Noise & Sensitivity) → Chapter 10 (Traceability & Certificates)
   • In-service monitoring & operations: Chapter 8 (Timebase Alignment) → Chapter 14 (SLO & Dashboards)
   • Cross-instrument harmonization: Chapter 12 (Cross-Comparison) → Appendix E (Uncertainty Propagation)
3. Cross-volume references: see Metrology.TimeBase v1.0, Metrology.Sync v1.0, Methods.Cleaning v1.0, Methods.Imaging v1.0.

III. Scope, Objects, and Dependencies

• Objects: signal chains of electrical/optical/acoustic/RF/microwave and multi-modal composite instruments (AFE/ADC/DAC/photoelectric conversion/RF chain).
• Inputs: device/channel configuration, references & standards, environment & operating conditions, calibration & raw measurement records.
• Outputs: calibration parameters, measurement results, u_c and U = k * u_c, certificates and manifest.instrument.*, compliance and contract assessment reports.
• Dependencies & interfaces: timebase/synchronization (tau_mono, ts, offset/skew/J), the two arrival-time formulations, data-cleaning contracts, and imaging chain mappings for PSF/OTF/MTF.

IV. Methodology Baseline and Unified Conventions

1. Dimensions & units: every field entering equations must declare unit(x) and dim(x); run check_dim(expr) prior to publication.
2. Uncertainty: adopt the GUM approach; report combined standard uncertainty u_c and coverage uncertainty U = k * u_c. Handle correlations via Jacobian propagation u_c^2 = J * Sigma * J^T.
3. Quantization & resolution: LSB = FS / 2^N, quantization noise u_q = LSB / sqrt(12); ENOB, SNR, SFDR per unified definitions.
4. Noise & bandwidth: define S_n(f), window functions, and equivalent noise bandwidth (ENBW); energy relation ( ∫ |H(f)|^2 S_n(f) df ) = Vn_rms^2.
5. Two arrival-time formulations (cross-volume canonical forms):
   • Constant factored out: T_arr = ( 1 / c_ref ) * ( ∫ n_eff d ell )
   • General form: T_arr = ( ∫ ( n_eff / c_ref ) d ell )
   • The manifest must log the difference delta_form between the two and assert delta_form ≤ tol_Tarr.
6. Numbering system: Postulates P70x-*, Minimal Equations S70x-*, Metrology Procedures M70-*, Implementation Bindings I70-*, Contracts C70-*.

V. Key Concepts and Unified Symbols (Selected)

• Signal chain & resolution: FS, LSB, N, ENOB, SNR, SFDR, INL, DNL.
• Noise & response: S_n(f), ENBW, H(f), BW_3dB, RBW, VBW, Vn_rms.
• Uncertainty & propagation: u(x), u_c, U = k * u_c, J, Sigma.
• Timebase & arrival time: tau_mono, ts, offset/skew/J, T_arr, gamma(ell), delta_form.
• Environment & corrections: RefCond, corr_env(x; RefCond), aging_rate.
• Traceability & certificates: TraceID, certificate.id, signature, TUR.

VI. Deliverables, Compliance Templates, and Audit

1. Deliverables:
   • Calibration & measurement reports: calibration curves/tables, u_c/U, conformity decisions, and guard-banding strategy.
   • Certificates & manifests: emit_certificate(...) and manifest.instrument.*, including device.*, results.*, unc.*, contracts.*, signature.
   • Operational dashboards: SLO/SLI indicators (availability, latency_ms_p99, drift, etc.) and alerting policy.
2. Compliance & audit:
   • Contract assertions assert_instrument_contract: uniqueness, dimensional consistency, arrival-time form difference, linearity/noise/bandwidth thresholds, certificate coverage factor.
   • Audit trail: TraceID spans prototypes/standards/data/certificates; file-level hash_sha256(blob) and signature.

VII. Versioning, Changes, and Compatibility

• Versioning policy: semantic versioning; breaking changes must be registered in Appendix F with migration guidance.
• Compatibility constraints: interfaces I70-* prioritize backward compatibility; when dimensions or metrology conventions change, publish compat_map and a recommended re-calibration window.
• Traceability closure: any change affecting U or conformity decisions must trigger re-signing and re-publication.

VIII. Document Structure and Cross-Volume References

1. Structure: Chapters 1–7 cover core signal-chain models; Chapters 8–12 address timebase, environment, comparison, and harmonization; Chapters 13–15 focus on interfaces, SLOs, and use cases; appendices detail interfaces, contracts, manifests, metrics, and uncertainty propagation.
2. Fixed cross-volume reference style (examples):
   • Timebase mapping: see Metrology.TimeBase v1.0, Chapter 5, S/T/I.
   • Sync servo: see Metrology.Sync v1.0, Chapter 6.
   • Cleaning contracts & publication: see Methods.Cleaning v1.0, Chapter 10.
   • Imaging mappings (PSF/OTF/MTF): see Methods.Imaging v1.0, Chapter 5.

IX. Ready-to-Release Criteria

1. All mandatory assertions hold:
   • check_dim(all) = true
   • U = k * u_c computed with k stated explicitly
   • Linearity, noise, bandwidth, and time-jitter meet C70-* thresholds
   • Arrival-time form difference satisfies delta_form ≤ tol_Tarr
   • Certificate and manifest.instrument.* are signed; TraceID ensures end-to-end traceability
2. Release action: freeze_release_certificate(certificate, tag) -> manifest.instrument, and register the audit log plus dashboard baselines.

Summary