本SAE推荐实施规程提供了用于公路上单挂车和多挂车组合的空气制动挂车和小车的说明和试验程序。本文件不适用于非公路应用。目的本文件提供了一种方法，用于确定拖车和小车供气系统在加注储液罐时的效率，以及在释放驻车制动器时（对于使用弹簧制动的储液罐）的效率。

This SAE Recommended Practice provides instructions and test procedures for air braked trailers and dollies used in single and multiple trailer combinations on highway. This document is not intended for off-highway application. Purpose This document provides a method of determining the efficiency of trailer and dolly air supply systems in filling reservoirs and, for those with spring applied parking brakes, in releasing parking brakes.