Measurement:Units

• Part of: Measurement:Main_Page
• Related to: Measurement:Unit_Identifiers

AOWIS systems, components, and data models MUST use the International System of Units (SI) as the canonical unit system.

SI is the globally accepted standard for scientific and technical measurement and is defined and maintained by the International Bureau of Weights and Measures (BIPM).

Purpose

This specification establishes a single authoritative unit system for all physical quantities represented by AOWIS.

The use of a single unit system reduces implementation complexity, eliminates ambiguity during data exchange, simplifies validation and testing, and improves interoperability between independent AOWIS implementations.

Requirements

REQ-MEAS-000: The International System of Units (SI) is the authoritative unit system for all physical quantities represented by AOWIS.

REQ-MEAS-001: All numerical values representing physical quantities within an AOWIS-compliant system MUST be represented using SI units.

REQ-MEAS-002: Implementations MUST produce results that are numerically consistent with SI-based processing.

REQ-MEAS-003: Implementations MUST NOT introduce conversion artifacts, rounding errors, or precision loss that are outside the documented precision of the measurement.

REQ-MEAS-004: Interfaces between AOWIS-compliant and non-AOWIS-compliant systems MUST convert all non-SI physical quantities to SI units before they become part of the AOWIS measurement model and MUST convert from SI units when exporting data to systems requiring non-SI units.

REQ-MEAS-005: User interfaces MUST clearly indicate the unit associated with every displayed or entered numerical value representing a physical quantity.

REQ-MEAS-006: Each physical quantity in AOWIS MUST be mapped to exactly one canonical SI unit.

Notes

External systems MAY use alternative unit systems. Any required conversion between such systems and AOWIS is performed at the system boundary in accordance with REQ-MEAS-004.