Measurement of a phase is necessary in a single or multiple balancing of rotating machines. Rate of phase shift is also very important because it can indicate presence of a critical speed. Amplification factor or log decrement in a certain mode can also be determined out of a rate of phase shift. Having a phase referent mark of complex rotating machines is especially important. Without the presence of phase signal it is impossible to determine which component of total vibrations is synchronous and which occurs due to external or subsynchronous vibrations. Using timing mark allows monitoring of amplitude and phase in order to determine critical speeds, amplification factors and balancing.
Key words: phase, amplitude, Bode plots, Nyquist plots, critical speeds, cascade plots, turbomachinery
Topic: ENGINEERING SCIENCES