Online monitoring with short operating cycle

The total cycle time for one sled to be raised from the bottom and the other sled to be lowered from the top is roughly 90 seconds. The sleds are loaded and unloaded simultaneously over the next 12 seconds and then they each begin the return cycle. That 90 second cycle is broken into three sections. The first 25 seconds is the initial acceleration from rest to full speed. The sleds are at full speed for the next 40 seconds, and then slow to a stop over the final 25 seconds. To ensure we are comparing the current spectra to the established average spectra (the expected pattern of frequencies and amplitudes), we need to maintain the same speed and load conditions for each test. Based on the 90 second cycle described above, the only period of time that meets that repeatable condition is the 40 second stretch when the sleds are at full speed.