Overview
ISO 2533:1975/Add 2:1997 is an addendum to the established ISO standard for the Standard Atmosphere, published by the International Organization for Standardization (ISO). This crucial addendum extends the defined standard atmosphere model down to -5000 meters altitude and provides standard atmosphere parameters as a function of altitude in both meters and feet. The document is a key reference for industries and professionals that require consistent atmospheric data for applications ranging from aviation to aerospace engineering.
This standard was developed under the guidance of ISO Technical Committee ISO/TC 20 (Aircraft and space vehicles), Subcommittee SC 6 (Standard atmosphere), in cooperation with the International Civil Aviation Organization (ICAO). It builds on the formulas, boundary values, and constants set in the original ISO 2533 and its preceding addenda.
Key Topics
- Extension to -5000 meters: The standard atmosphere tables now include negative altitudes, important for applications below mean sea level.
- Standard atmosphere in feet: For global consistency and to support users operating in different measurement systems, the document offers values not only in meters, but also in feet - spanning from -16,500 ft to +262,500 ft.
- Comprehensive atmospheric parameters: Parameters provided include temperature, pressure, density, acceleration due to gravity, speed of sound, dynamic and kinematic viscosity, and thermal conductivity, across a broad range of altitudes.
Applications
ISO 2533:1975/Add 2:1997 is widely used in:
- Aerospace Engineering: Standard atmosphere data is fundamental to performance calculations, simulation, and testing for both aircraft and spacecraft.
- Aviation: Airlines, airplane manufacturers, and aviation authorities use standard atmosphere tables for flight planning, certification processes, and avionics calibration.
- Meteorology & Environmental Studies: Provides a baseline for weather modeling, climate studies, and atmospheric research.
- Industrial Design: Essential reference for engineering calculations where variations in atmospheric conditions impact design safety and efficiency, such as HVAC system sizing or the design of high-altitude installations.
- Education & Research: Serves as a reference dataset for teaching, academic research, and laboratory work involving atmospheric science and engineering.
Related Standards
For broader or complementary use, consider referencing these related standards:
- ISO 2533:1975 (Standard Atmosphere): The foundational standard defining atmospheric properties up to 80 km.
- ISO 2533:1975/Add 1: Prior addendum outlining intermediate extensions and clarifications.
- ICAO Standard Atmosphere: Developed in close collaboration with ISO, commonly used in international civil aviation.
- ASME and SAE Atmospheric Standards: Often referenced in US-based aerospace and engineering contexts.
Practical Value
Implementing ISO 2533:1975/Add 2:1997 ensures that calculations, simulations, and compliance checks are based on internationally recognized and consistent atmospheric models. It aids in harmonizing design and operational practices across organizations, countries, and industries. The dual-system (meters and feet) approach supports global interoperability and fulfills regulatory as well as engineering requirements.
By referencing this standard, users benefit from reliable, peer-reviewed data reflecting the best international consensus, facilitating safe, efficient, and coordinated activities in aviation, aerospace, meteorology, and related disciplines.
Open preview (PDF)Standard Atmosphere — Addendum 2: Extension to - 5000 m and standard atmosphere as a function of altitude in feet
