They are useful for tracking your progress toward coverage goals, and for detecting coverage erosion.
这对于追踪您的进程朝向覆盖率数据目标的情况，以及发现覆盖率的破坏非常有用。
2
Tracking and erosion test on insulators and shed material was made under service condition.
结合运行实际，对复合绝缘子及伞套材料的耐漏电起痕和耐电蚀损性进行了试验。
3
This article introduces the test for tracking and erosion of polymeric housed metal oxide arresters is described Some phenomena in the test have been analysed.