本SAE航空航天信息报告（AIR）涵盖并仅限于在温度低于500华氏度的临界和亚临界气流条件下空气的行为。该空气旨在提供有关在临界和亚临界气流条件下测量空气所用的适当类型的试验设备和计算程序的基本信息和理论背景，在喷气发动机起动应用中通常会遇到这种情况，并为试验装置的构造提供指导。此外，还提出了一种简化技术人员计算的方法。

This SAE Aerospace Information Report (AIR) covers, and is restricted to, the behavior of air under conditions of critical and subcritical flow at temperatures less than 500 degrees F.This AIR is intended to provide basic information and theoretical background on proper types of test equipment and calculation procedures for use in measuring air in critical and subcritical flow conditions, as are usually encountered in jet engine starting applications and to provide guidance in the construction of test apparatus. Additionally, a method for simplifying the calculations performed by technicians is presented.