Vibration pickups

From the information given so far it will be appreciated that ex­actly how the vibration is measured and the equipment used becomes of prime importance. The actual “pickup” or trans­ducer is a sensing device which converts the mechanical vibra­tion into electrical energy. Several types exist as follows:

Seismic velocity pickup

This consists of a coil of wire supported by springs in a magnetic field created by a permanent magnet which is part of the case. For details of the construction see Figure 15.7.

When it is held against or attached to a vibrating machine, the permanent magnet, being attached to the case follows the vi­bratory motion. The coil of wire or conductor being supported

 

COMPRESSION TYPE

 

Triangular Centre

Past

 

Preloading Ring

Piezoelectric Element in Shear Seismic Hass

 

SHEAR TYPE

 

Vibration pickups Vibration pickups Vibration pickups Vibration pickups

Function of frequency squared they are most sensitive to high frequency vibration.

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