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 real-time processing of AE Hits and Events going through the applied digital 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.