Vibrating element transducer.

摘要

A vibrating element transducer is provided in which a vibrating element (28) and a substantially non-vibrating reference element (30) are positioned side by side and illuminated via an optical fibre (31). The surfaces of the vibrating element (28) and the reference element (30) are formed at slightly different distances from the end of the optical fibre (31). The differing distances are arranged such that interference between the light reflected from the vibrating element and from the reference reflector can be used to determine the frequency of vibration of the vibrating element. <IMAGE>