采用“圆柱上的球”原理，将不旋转的钢球固定在垂直安装的卡盘中，并使用施加的载荷施加在轴向安装的钢瓶上。试验气缸以固定速度旋转，同时部分浸入润滑油箱中。这将使气缸保持湿润状态，并将试验流体的润滑膜持续输送至钢球和气缸接口。试验球上产生的磨痕直径用于测量流体的润滑性能。通过调整操作条件，该设备可用于再现两种不同的磨损机制；轻微和严重磨损，因此ALTE有能力评估润滑剂在这方面的性能。 下面介绍这些机制。

Employing "ball-on-cylinder" philosophy, a non-rotating steel ball is held in a vertically mounted chuck and using an applied load is forced against an axially mounted steel cylinder. The test cylinder is rotated at a fixed speed while being partially immersed in a lubricant reservoir. This maintains the cylinder in a wet condition and continuously transports a lubricating film of test fluid to the ball and cylinder interface. The diameter of the wear scar generated on the test ball is used as a measure of the fluid's lubricating properties.The apparatus can be used, by adjusting the operating conditions, to reproduce two different wear mechanisms; mild and severe wear, the ALTE therefore has the ability to assess a lubricant's performance in that regard. These mechanisms are described below.