with Applications, 5th Edition by William
Thomson | PDF
Fast Fourier Transform (FFT) analyzer - answer-A microprocessor capable of displaying the FFT
of an input signal.
order - answer-A multiple of a running speed (rpm) frequency.
logarithmic amplitude spectra - answer-Amplitude signals displayed in powers of ten.
vibration velocity - answer-The rate of change of displacement of a vibrating object.
trending - answer-A graphic display used for interpretation of machine characteristics.
waveform - answer-A graphic presentation of an amplitude as a function of time.
vibration - answer-A continuous periodic change in displacement with respect to a fixed
reference.
velocity transducer - answer-An electromechanical device that is constructed of a coil of wire
supported by light springs.
vibration signature - answer-A set of vibration readings resulting from tolerances and play
1
, within a new machine.
alignment - answer-The location (within tolerance) of one axis of a coupled machine shaft
relative to that of another.
Fast Fourier Transform (FFT) - answer-A calculation method for converting a time waveform
into a series of frequency vs. amplitude components.
time domain - answer-An amplitude as a function of time.
hertz (Hz) - answer-A measurement of a frequency equal to one cycle per second.
displacement (vibration) - answer-The measurement of the distance (amplitude) an object is
vibrating.
phase - answer-The position of a vibrating part at a given moment with reference to another
vibrating part at a fixed reference point.
oscillator - answer-A device that generates a radio frequency (RF) field that, when sent to a
probe tip, creates eddy currents.
frequency - answer-The number of cycles per minute (cpm), cycles per second (cps), or
multiples of rotational speed (orders).
peak-to-peak displacement - answer-The distance from the upper limit to the lower limit of a
vibration.
2