Fast as a flash
Transient measurements at the physical limits require dedicated stimuli to excite the device under test (DUT). A continuous sine sweep can be as short as 200 ms for a comprehensive measurement. However, DUTs may need a longer test time to develop reliable symptoms at critical frequency ranges (e.g. high displacement for Rub & Buzz). These frequencies can be emphasized using a variable sweep speed. Thus, the test speed depends on the DUTs, not on the test system.
- Comprehensive test in 200 ms
- Variable sweep speed
- Minimized time between last sample and verdict
- Basis for 100 % testing
The figure below illustrates a sinusoidal sweep stimulus (chirp) with a speed profile which is optimal for loudspeaker measurements. 90 % of the available measurement time (180 ms) is used to measure the loudspeaker below 200 Hz, but only a very short measurement time (20 ms) is required to measure the loudspeaker at higher frequencies. The chirp, using the speed profile, excites the loudspeaker at all frequencies and provides sufficient energy to activate Rub & Buzz defects.
A complete acoustical and electrical test can be accomplished in far less than 1 s. Ultra fast testing saves measurement time which can be used for repeating the test to gain ambient noise immunity.