Thanks to all respondents. In reply the accl. is stud mounted,is usable above 20khz,no internal resonance below 20khz.Accls.usable to 75khz and other instrumentation confirm findings.Modal study has been done and now being restudied. MikeyP-your perception that I was confused by thinking...
WE MONITOR VIBRATION ON THE DIE BLOCK OF A ROTARY PUNCH MACHINE PUNCHING .015IN STEEL AT 800/SEC.ACCL. HAS 35KHZ RESONANCE AND MONITOR IS FFT WITH UPTO 20KHZ BW,UPTO 32OO BINS AND TO 51.2KHZ SAMPLING RATE.PUNCH VELOCITY IS SUCH THAT SHEARING EDGE THEORITICALLY PASSES THRU STEEL IN .0000102...