本SAE推荐规程确立了封闭式驾驶室卡车、客车和多用途车辆除霜系统的统一试验程序和性能要求。它仅限于可在商用实验室设施的统一测试设备上进行的测试。对于除霜系统的实验室评估，当前的工程实践规定，在挡风玻璃和左右侧窗上涂抹一层已知厚度的冰涂层，以提供更均匀和可重复的测试结果，即使在实际条件下，这样的涂层在驾驶前必然会被刮掉。因此，试验条件比实际条件更为严重，除霜系统必须仅能保持一个干净的观察区域。由于大多数此类车辆运行的特殊性（车辆通常存放在车库中或在行驶前进行预热），以及在稳定温度下除霜- 道路运行状态是主要问题，已采用了假设发动机在车辆行驶前处于预热状态的测试条件。在本推荐规程中，有两种方法可用于生产热冷却液。在同一辆车上使用这两种方法进行测试，不一定会得到相同的结果。许多车型都配备了可选发动机，每个发动机的冷却液温度和流量都不同。如果进行试验是为了比较一种除霜器设计与另一种除霜器设计的性能，则外部冷却液源方法（试验A）将产生最具可比性的结果。如果进行测试是为了验证特定车型上除霜器的安装是否具有特定发动机，则使用发动机加热冷却液（测试B）将更合适。本文件将根据车辆除霜器测试程序的技术进步要求进行审查和修订。

This SAE Recommended Practice establishes uniform test procedures and performance requirements for the defrosting system of enclosed cab trucks, buses, and multipurpose vehicles. It is limited to a test that can be conducted on uniform test equipment in commercially available laboratory facilities. For laboratory evaluation of defroster systems, current engineering practice prescribes that an ice coating of known thickness be applied to the windshield and left- and right-hand side windows to provide more uniform and repeatable test restults, even though¿¿¿under actual conditions¿¿¿such a coating would necessarily be scraped off before driving.The test condition, therefore, represents a more severe condition than the actual condition, where the defroster system must merely be capable of maintaining a cleared viewing area. Because of the special nature of the operation of most of these vehicles (where vehicles are generally kept in a garage or warmed up before driving), and since defrosting under steady-state over-the-road operations is the main concern, test conditions have been adopted which assume that the engine is warm before the vehicle is driven.There are two options for producing hot coolant in this recommended practice. Testing using these two approaches on the same vehicle will not necessarily provide identical results. Many vehicle models are offered with optional engines, and each engine has varying coolant temperatures and flow rates. If the test is being conducted to compare the performance of one defroster design to another defroster design, then the external coolant source approach (Test A) will yield the most comparable results. If the test is being conducted to validate the defroster installation on a specific vehicle model with a specific engine, then using the engine to heat the coolant (Test B) will be more appropriate.This document will be reviewed and revised as technological progress in vehicle defroster test procedure requires.