Voice Recording, available in Data Physics’ SignalCalc Dynamic Signal Analyzer and SignalStar Vibration Controller software as part of throughput to disk analysis, allows the user to utilize an input channel to record voice as a commentary during the test.
High profile tests often require customers to monitor key events that happen during the test. There are a variety of possible events. Some examples are a resonance of a component in a satellite, a bearing problem on a turbo compressor, and a gear mesh situation in a rotating machine. Monitoring an event involves taking a lot of notes during testing such as the type of event, time it happened, and length of the event. The notes will help the user identify the event during post analysis. Not only is the process time consuming, but it poses the risk of misplacing the documentation at a later time.
An alternative approach to manual book keeping is to use an external tape recorder to record voice data. However, it adds unnecessary complexity and increases the amount of time needed for testing.
The voice annotations of the Voice Recording feature provide a good solution to this problem. The annotations are synchronized in time with the data collected across all channels. During playback, the voice recording may be used as a cue channel to identify significant events guiding the playback analysis process.
The test process is carried out in 3 steps:
1. Testing and Recording Phase – In addition to the usual test setup, a microphone is connected to one of the input channels to record voice. A low cost ICP microphone is ideal for recording voice since the analyzer or controller can power the microphone. While the test is in progress, the voice notes made by the operator for various events are recorded and stored with the throughput data.
2. Event Identification (Playback DAC mode) – Events can be marked by listening to the voice channel data via a speaker in playback DAC mode. While listening to the commentary, the add marker button on the voice channel menu adds the time associated with the event. The below list of events are identified (see Figure 1) with the event time and a comment for a sine sweep test on an airplane.
Though the condensed display of data on the throughput file gives a visual indication of an event, it is tough to associate it with the actual event without the voice commentary.
3. Analyzing the Marked Events (Playback Analysis) – Identified events can be analyzed by selecting them in the voice channel marker menu and using the start and stop position buttons. The start and stop times may be further refined using the cursors on the throughput panel for analysis.
Voice recording is a valuable tool built into the throughput record and playback option. It allows the user to record various events during the test as voice annotations, minimizing the need for external documentation.
-Kalyan Vitta, Senior Applications Engineer