Noise
Noise is a sound that is loud or unpleasant. The unit for noise is expressed in decibels, dB.
where,
P = measured sound pressure in Pa
Pref = reference sound pressure, 20μPaPump noise measurement is shown in Figure 1. The measurement is taken 1 meter from the pump from the front, back, and side positions. Prior to running the pump, the background noise level is taken. The pump’s noise level is then compared to the background to determine the incremental noise of the pump.
The sources of the noise of the pump come from the noise of the fluid in the pump and the impact of the impeller on the thrust ring. From the motor, the noise comes from electromagnetic sound, the rotation of the cooling fan, the bearing, and the friction of the oil seal.
Figure 1