Answer:

Explanation:

Vibration is the back and forth or repetitive motion of an object from its POINT of rest.

When a force is applied to the mass, it stretches the spring and moves the weight to

the lower limit. When the force is removed, the stored energy in the spring causes the

weight to move upward through the position of rest to its upper limit. Here, the mass

stops and reverses direction traveling back through the position of rest to the lower

limit. In a friction-free system the mass would continue this motion indefinitely. All

real systems are damped, that is they will gradually come to their rest position after

several cycles of motion, unless acted upon by an external force. The characteristics

of this vibratory motion are period, frequency, displacement, velocity, acceleration,

amplitude and phase. Continued vibration of this spring mass system would only

repeat the characteristics shown in this single cycle.

All rotating machines produce vibrations that are a function of the machine dynamics,

such as the alignment and balance of the rotating parts. MEASURING the amplitude of

vibration at certain frequencies can provide valuable INFORMATION about the accuracy

of shaft alignment and balance, the condition of bearings or gears, and the effect on

the machine due to resonance from the housings, piping and other structures.

Vibration measurement is an effective, non-intrusive method to monitor machine

condition during start-ups, shutdowns and normal operation. Vibration analysis is

used primarily on rotating equipment such as steam and gas turbines, pumps, motors,

compressors, paper machines, rolling mills, machine tools and gearboxes. Vibration

analysis is used to determine the operating and mechanical condition of equipment. A

major advantage is that vibration analysis can identify developing problems before

they become too serious and cause unscheduled downtime. This can be achieved by

conducting regular monitoring of machine vibrations either on continuous basis or at

scheduled intervals. Regular vibration monitoring can detect deteriorating or defective

bearings, mechanical looseness and worn or broken gears. Vibration analysis can also

detect misalignment and unbalance before these CONDITIONS result in bearing or shaft

deterioration. Trending vibration levels can identify poor maintenance practices, such  

as improper bearing installation and replacement, INACCURATE shaft alignment or

imprecise rotor balancing.