VMI VIBER X5 MKIII, Instrument Manual, Page: 89 / 121

89
The pressure section in a paper machine involves the suction roll, the pressure roll and the
felt. By measuring three separate synchronous spectrum with the tachometer placed on
the three parts, the two rollers and the felt, you can find the source of the vibration and
also measure when patterns occur in the felt, because each of the three spectra will only
show vibrations synchronous with their own speed.