Performing the measurement

3. Performing the examination

After starting the measurement, the measured parameters of the detected AE Hits and the sampled values of the environmental parameters are stored in the opened measurement file. Parallel to this goes the real-time processing of AE Hits and Events going through the applied parametric filters: calculation of derived parameters, listing of the selected parameter group, building of the predefined graphs, localization of the AE sources and theirs positioning on the localization map. This can be checked and controlled on the computer screen. You can select an AE channel and send test pulses to imitate an active AE source. It is also possible to perform most of the activities listed in connection with the examination preparation: you can enable or disable the AE channels, change the gain mode, the threshold level, or change the sampling time of the environmental parameter channels. You can insert new parameter filters or alarm conditions or correct existing ones; you can define new localization maps, parameter groups, graphs, or freely switch between on-screen appearances. Changes to the instrument setting, and the inserted textual comments, are stored immediately in the measurement file.
While measuring, you can take snapshots of the AE channel signals – whether from all AE channels of a device at a time. Recorded snapshots will also be included in the measurement file. Based on the patterns, frequency spectrum analysis (FFT) can be requested, or correlation between the patterns of selected channels can be examined.
Occasionally, the inspected object is related to noisy events: visual inspection or repair work must be carried out and the examination becomes impossible because of noises from impacts and friction. It is possible to temporarily disable the measurement recording without interrupting the test and then re-enable the recording of the new AE data after liquidation of disturbance conditions. During the measurement, you can make short notes, such as events, changes in measurement conditions, and unregistered environmental parameters. These text comments are also added immediately to the measurement file.
The most important task of the system is to save the measurement data completely to the measurement file during the measurement. The execution of this task is not hampered by the real-time calculations of the evaluation during the examination. If the AE activity is significantly increased during the test, the evaluation may be gradually lagging behind the data collection and storage. The magnitude of this delay is indicated by an indicator on the screen. You can speed up your evaluation by disabling data listing or temporarily disabling the graphing feature.
When the examination is completed, the measurement file is closed. In continuous monitoring mode, i.e. after start of a cyclic sequence of measurements, each individual measurement lasts for a predetermined time, then restarts after a given wait pause.

  • Main functions performed by the software during measurement execution:
    • Start (using the specified measurement results file), suspend, continue and stop measurement
    • Reception and immediate recording on the computer’s disk of all information received from the system’s instruments, including the full setting in time of starting the measurement, corrections to the settings and messages entered by the operator during the measurement
    • Reading measurement data from the computer’s disk and evaluation of them
      • Parametric filtering of received AE Hits
      • Formation and processing of AE Events and parametric filtering of them
      • Alarm generation
      • Tabular presentation of results
      • Graphic presentation of results
      • Parametric filtering of AE Events for source location. Presentation of results on location maps
      • Registration and visualization of original waveform (snapshots) on AE channels.
  • Additional functions performed by the software during measurement execution:
    • Temporary break in recording of measurement results at operator’s command
    • Displaying the lag in processing of measurement results from their recording at high AE intensity
    • Temporarily stopping presentation of measurement result graphs at operator’s command
    • Separate “Monitor” window
      • Displaying current time from the start of measurement
      • Start, stop and reset the stopwatch
      • Selection of a parametric input channel and display of the current signal level.
    • Sensor test mode
      • Start and stop the issuance of the sensor test pulses by the selected AE channel. AE Hits resulted from the sensor test pulses are recorded in the measurement file
        • Selection of AE channel for the sensor test mode, setting repetition period and parameters for test pulses
      • Setting up and launching automatic testing of health of the entire system at a long absence of AE activity in the continuous monitoring mode. AE Hits from the test are not recorded in the measurement file. A special warning signal can be generated.
  • Operator’s actions during measurement:
    • Start, suspend, continue and stop the measurement, temporarily stop and continue presentation of measurement result graphs
    • Correction of threshold values ​​for AE Hit detection
    • Work with tables, graphs and location maps. Correction of settings of these forms of measurement results’ processing and displaying
    • Work with parametric filters for AE Hits and Events. Correction of settings of these forms of measurement results’ filtering
    • Work with parametric filters for locating. Correction of settings
    • Work with parametric filters for Alarming. Correction of settings
    • Saving changes to the settings with just one click in the working file, or in new file with a different name
    • Starting registration of original waveform (snapshots) on AE channels. Work with waveform display. Display of frequency composition (FFT). Calculation of correlation between signals of selected AE channels. Correction of settings
    • Entering short text comments and messages that are recorded in the file of measurement results
    • Turning on and off a separate window “Monitor” and working in it
    • Work in Sensor test mode.