本试验旨在确定触点工作环境中低电平开关条件下的电触点可靠性。低电平开关电路是一种电压和存储能量足够小的电路，这样一对触点的电阻就不会受到与电流或开关有关的电气现象的影响。这种电路的电压或电流太低，不会导致触点发生任何物理变化； 触点电阻仅受触点上机械作用引起的触点变化的影响。导致电触点之间产生电弧的电负载以多种方式影响接触面，主要有利于降低接触电阻，因为触点上的绝缘膜和小粗糙凸起区域被烧掉或熔化，从而形成更均匀、更大的接触面。在低电平条件下，这种电弧的优点和偶尔的缺点都将消失。 如果低电平负载和中间或功率负载同时施加在同一部件上的不同触点对上，则低电平条件的可靠性可能会受到影响，因为在同一外壳或相邻区域中，在较大负载下运行的触点周围蒸发会导致异物沉积，由于低电平触点可能会因其环境的变化而显影，因此在与使用环境类似的环境中对触点进行测试。 该试验绝不反映中间或“最小”电流区域的接触能力，并且在规定时，不应被视为该区域试验的替代品。

This test is conducted for the purpose of determining electrical contact reliability under low-level switching conditions in the environment in which the contacts operate. A low level switching circuit is one in which the voltage and stored energy are sufficiently small so that the resistance of a pair of contacts is not affected by electrical phenomena associated with the electrical current flow or the switching. Such a circuit is also one where the voltage or the current is too low to cause any physical change in the contacts; contact resistance can only be affected by changes in the contacts caused by mechanical action on the contacts. Electrical loads, which result in arcing across electrical contacts, affect contact surfaces in many ways, mostly favorable to reduction of contact resistance, since insulating films and small rough raised areas on the contact are burned away or melted down, to reform as a more even and larger contact surface. Under low-level conditions, the advantages, as well as the occasional disadvantages of this arcing will be absent. If low-level loads and intermediate or power loads are to be applied to different pairs of contacts on the same component part simultaneously, reliability of the low-level conditions can be impaired due to deposition of foreign materials resulting from vaporization surrounding the contacts operating at larger loads in the same enclosure or in an adjacent area, because of this fact, and because low-level contacts may develop films as a function of their environment, the contacts are tested in an environment similar to that in which they are used. This test in no way reflects the contact capability in the intermediate or "minimum" current area and shall not be considered as a substitute for testing in this area when specified.