| FFT V-1-2 |
Measuring natural vibration frequency by
sine sweep using internal signal from an exciter controller. |
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- Sweep excitation is one of the methods to measure
natural frequency of parts etc. The sweep averaging
function of the DS-3000 series calculates the
frequency response function of the vibration on the
excitation table and acceleration of measurement object
by sine sweep.
- For instance, a test is performed with the
controller of the vibration exciter set to 10 Hz to 200
Hz sine sweep and the acceleration of 30 m/s2
and then the frequency response function of vibration of
the excitation table and acceleration of the part is
measured using the sine sweep averaging function in sync
with the internal signal of the DS-3000 series.
- The sweep time must be taken long time (approx. from
several minutes to several tens of minutes). Because a
measurement will take long time in low frequency range,
and it needs to minimize the frequency variation since
excitation frequency of vibration exciter and sampling
frequency of the DS-3000 series are measured
asynchronously.
- You can see several peak values depending on a shape
of a measurement object. Damping ratio also can be
calculated by using half-power bandwidth method.
Moreover, integrating function enables display and
evaluation of velocity/force (mobility),
displacement/force (compliance), force/acceleration
(dynamic mass), force/velocity (mechanical impedance),
force / displacement (dynamic rigidity).
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Model |
Product name |
Remarks |
| 1 |
DS-3000 series |
Multi-channel Data Station |
DS-3204 4ch Main unit
DS-0321 FFT Analysis function
DS-0322 Tracking function
DS-0350 Recording function
USB 3.0 Cable (2 m) |
| 2 |
NP-3211 |
Accelerometer with built-in preamplifier |
Ultra compact, lightweight (0.5 g), frequency
range: 0.3 Hz to 20 kHz ±3dB, signal cable (3 m)
(included) |
| 3 |
NP-0020 |
Signal cable extension adapter |
The adapter for signal cable extension (between
the NP-0153 and the cable for the NP-3211). |
| 7 |
NP-0153 |
Signal cable for the NP-0020 |
5 m, -25 to +160˚C |
| 8 |
NP-0021 |
Miniature/BNC conversion connector |
Converts the NP-0153 signal cable terminal to
BNC connector and input to the DS-3000 series
BNC connector. |
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Remarks
The DS-3000 series needs a PC separately.
More accurate measurement is possible if an excitation
controller has an external signal input connector.
Synchronous measurement with the sweep is enables by input
of sine sweep signal from the DS-0371 (built-in, option)
(signal output unit for the DS-3000 series).
Other models of FFT analyzer can be applicable (the DS-3000
with tracking analysis function, octave analysis function,
the CF-3650/3850, the CF-9200/9400 series). |
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