FFT Applications
Q-1-3 OK/NG judgment of a motor on a inspection line
- This example shows how to make OK/NG judgment automatically by power spectrum of vibration during motor in operation. The Figure 1 shows the time waveform and its power spectrum of an OK (non-defective) product. The time waveform and its power spectrum of an NG product are shown in the Figure 2.
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Some particular peaks are existing in higher frequency of the NG product than that of the OK product. The CF-4700A FFT comparator can make OK/NG judgment by setting judgment level around the frequency of target spectrum.
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The block comparator function makes OK/NG judgment by the judgment block area (maximum setup: 20 blocks) set in a certain frequency range and level range. Level, peak level, peak max, section overall, areal rate of content judgment methods are available for each block. You can make OK/NG judgment with the most appropriate one selected from the five judgment methods. Also the digital I/O function enables control via PLC using comparator output.
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The measurement results can be stored into a PC via LAN or RS-232C interface.
Product list
| Model | Product name | Remarks | Qty | |
|---|---|---|---|---|
| 1 | CF-4700A | FFT Comparator | 1 | |
| 2 | NP-3418 | Accelerometer with built-in preamplifier | 1 | |
| 3 | NP-0021 | Miniature/BNC conversion connector | 1 |