| 1. | "Log interval" selector and field: The log interval defines the time between two successive recorded points when the instrument is recording signal statistics or RMS level statistics. When recording either type of statistics the min, max and average are reset at the beginning of each log interval. Then the instrument observes the signals or levels for the duration of the log interval, and updates the min, max and averages accordingly. At the end of the log interval the selected statistics are written to memory. Then the next log interval is started… and so on until the recording is stopped or the memory is exhausted. The log interval is only relevant when recording statistics. When recording raw signals the time between two successive samples is simply the sampling period. The log interval can be adjusted from 125 ms to 2 H in increments of 125 ms. Note: When recording statistics the amount of memory consumed is inversely proportional to the log interval. The Memory-Depth indicator in the Setup panel of the Instrument Manager automatically calculates the overall recording time as a function of the selection. |
| 2. | "Content of recording" buttons and check boxes: You must first select one of the three following buttons. These buttons specify whether raw signals, signal statistics or RMS level statistics are being recorded. In either case the user must choose the axes, and optionally the types of statistics to record. To select or deselect an axis or statistic, simply press on the corresponding check boxes. Note: In order to record inclinations select “Acceleration”, then select “Signal peaks & avg” and select at least the X-avg, Y-avg and Z-avg selectors. The inclinations are calculated from those acceleration measurements. The amount of memory consumed while recording is proportional to the number of channels and statistics selected. |
| a. | "Raw signal" button: The signal (acceleration or velocity) is recorded at the sampling frequency. |
| b. | "Signal peaks & avg" button: The Signal Statistics processing captures the min, max and average of the acceleration or velocity signal over an adjustable recording (log) interval. For each new interval the statistics are cleared, then the statistics are updated during the course of the interval, then at the end of the interval the statistics are recorded, and a new interval is started. |
| c. | "RMS peaks and avg" button: the RMS-Level signal is squared to calculate the instantaneous power. The instantaneous power is low-pass-filtered with an adjustable time constant to produce an average. A short time constant provides an average that is capable of tracking fast transients, while a longer time constant provides a smoother and less noisy average. A typical fast time constant is around 100ms. While a typical long time constant is around 1s. Finally the square-root of the power is taken to present RMS vibration or velocity levels. The RMS vibration levels can be displayed in linear or dB scale. |
| d. | Axes check boxes: From the "Signal type" and the previous selection, the maximum recording content for the three axes is automatically checked. You can reduce the recording to the axes you want and Max, Avg, Min values you want. |
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High-Pass:
