FFT Applications

FFT         OK/NG judgment, quality control (using PC or PLC* etc.)

Q-1-10      Quality control of power steering pump

  • When a hydraulic pump for the automotive power steering is driven by a drive motor to generate hydraulic pressure, pulse pressure vibration occurs. The vibration detected by the NP-3418 accelerometer with built-in preamplifier and the rotation pulse of the drive motor detected by a rotation detector are sent to the CF-4700A FFT comparator. The peak hold function of the CF-4700A detects amplitude of the first to the n-th order component of rotation for pulse pressure vibration. ON/NG judgment power steering pump is made depending on the peak level.

  • The block comparator function makes OK/NG judgment by the block area (maximum setup: 20 blocks) set in a certain frequency range and level range. Six kinds of judgment methods (level, peak level, peak max, insideMax, partial overall or area rate of content) are available for each block. 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.


Product list

  Model Product name Remarks Qty
1 CF-4700A FFT comparator Input channel: 1ch, frequency range:1 Hz to 40 kHz, dynamic range: 90dB 1
2 CF-0471 Tracking function Constant width/constant ratio tracking, the number of maximum analysis orders: 800 1
3 NP-3418 Accelerometer with built-in preamplifier Compact and light weight type (approx. 1.9 g), frequency range: 0.8 Hz to 16 kHz ±3 dB, resonance frequency: approx. 40 kHz 1
4 NP-0021 Miniature･BNC conversion connector Conversion cable between miniature connector of the NP-0150 series signal cable end and BNC connector 1
5 HT-5500 Handheld type digital tachometer Contact and non-contact type, LCD 5-digit, 12mm Reflective marks x 1 sheet (12-mm square; 25 pcs.) and carrying case are provided as standard. 1
6 AX-501 Analog output cable For rotation pulse signal for the HT-5500(2m) 1