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.

Some particular peaks are existing in higher frequency of the NG product than that of the OK product. The CF-4700 FFT comparator can make OK/NG judgment by setting judgment level around the frequency of target spectrum.

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.

The measurement results can be stored into a PC via LAN or RS-232C interface.