# Tiga Parameter Utama Dalam Pengukuran Vibrasi

DUNIAPEMBANGKITLISTRIK.COM - There are three main parameters in the measurement of vibration of a machine, namely: displacement, velocity and acceleration that must be considered before analyzing the causes of abnormal vibrations.

Displacement (Vibration Distance)

Is the distance traveled by alternating movements (vibrations) at a certain time period. This parameter is obtained by measuring the distance of the rotation of the rotating point of the disc caused by the centripetal force through the equation:

Displacement (µ) = A Sin (2πft)

Where,

A = Long distance of shift radius. (µ)

f = Frequency of alternating movements. (Hertz)

t = time. (second)

In the measurement of vibration, displacement parameters can only measure peak to peak displacement, which is the distance from positive maximum to negative maximum or equal to 2 x A.

Velocity (Vibration Speed).

Is the speed of movement back and forth at a certain time period. The speed parameter always changes along the distance traveled, where the maximum positive position and the maximum negative speed is zero, while in the position of movement through the neutral area the speed is maximum. The speed of vibration can be determined through the equation.

Velocity (mm / s) = 2πfA Cos (2πft)

Please note that in making measurements, vibration velocity can only measure the maximum speed or called peak velocity.

Acceleration.

Is the acceleration of movement back and forth at a certain period of time. Acceleration always changes along the distance that it goes through, where the maximum at the time of displacement reaches a positive maximum or close to a maximum negative. The vibrational acceleration can be determined through the equation.

Acceleration (mm / s2) = - (2πf) 2 A Sin (2πft)

In measuring vibrations, vibrational acceleration can only measure maximum vibration acceleration or called peak acceleration.

The Relationship Between Displacement, Velocity and Acceleration

In the condition of a machine that is vibrating, these three parameters are always present and cannot stand alone. All three have a differential sequence relationship starting from displacement, velocity and acceleration.

The three formulations have been described above, and if described each is a sinusoidal curve as shown below.

By using a sophisticated analyzer when measuring vibration on a machine, sinusoidal graphics will be found as above.