In practice, that have yet to develop absolute standards of gears, statistical average can take advantage of in situ measurements of data, development of appropriate criteria, use this method to determine the standard known as relative values.
Relative standards require gear boxes measuring point in the same place at different times measured amplitude compared with amplitude under normal conditions, when compared to the measured values and normal values up to a certain extent, judged to be a State. Like the standard value when the actual value is 1.6~2 times bigger than normal are required to attract attention, reaches 2.56~4, hazard, and so on. As to the specific uses are in accordance with 1.6 times ranking rank or according to twice times times, depending on gearbox depending on the requirements, crude device (for example, mining machinery) using multiple high ratings.
In practice, in order to achieve the best results, you can use either of the above methods, in order to contrast, a comprehensive evaluation.