Shear

• Shear vibration accelerometers subject the piezoelectric material to shear force, or force applied parallel to the face of the material. The piezoelectric crystals are sandwiched between a center post and one or more masses.
  
  

Compression

• Compression vibration accelerometers, on the other hand, subject the piezoelectric material to compression force, or force that causes it to become compacted or squashed. The piezoelectric crystals rest on a flat base and are loaded with a mass held in place with a stud.
  
  

Considerations

• Historically, compression vibration accelerometers were easier to assemble and therefore more popular than shear vibration accelerometers. However, shear vibration accelerometers typically perform better, so shear vibration is the technology of choice for modern accelerometers.