Vibrating sensor
AssigneeLucas Industries public limited company
InventorsAlan J. Cook, Robert A. Pinnock
Life of this patent
Estimating the term…
Abstract
A vibrating sensor comprises an elongated element arranged to vibrate at a frequency dependent upon an external stress applied to the sensor, and an optical fiber for coupling light into an end of the element to excite it into vibration. A light-absorbing layer is provided on a longitudinal surface of the element such that the element will change its configuration, e.g. by bending, as the layer absorbs light and heats that side of the element, this alteration in configuration causing a reduction of radiation which is absorbed so that the element restores. The element may define a Fabry-Perot interferometer between its opposite ends.
Claims14
A vibrating sensor comprising:
- an elongate element for vibrating, said elongate element having two ends;
- means for coupling electromagnetic radiation into one end of said elongate element, the elongate element including, along a longitudinal surface thereof, a layer which absorbs at least a portion of said electromagnetic radiation, said elongate element having a configuration and, responsive to said layer absorbing at least a portion of said electromagnetic radiation, altering said confirmation;
- and
- means for reducing the radiation absorbed by said layer as said configuration of the elongate element alters in response to absorption of the radiation by said layer.
A vibrating sensor, said sensor comprising:
- a source of electromagnetic radiation;
- an elongate element having two ends and a neutral bending axis extending along a longitudinal axis, said element including a means for selectively absorbing energy from said source of electromagmetic radiation and the amount of energy absorbed dependant upon the position of the elongate element;
- and
- a means for mounting said elongate element, where said means for selectively absorbing comprises a means for asymmetrically heating, with respect to said neutral axis, said elongate element causing said element to move in a direction from an unheated position towards a heated position during an increase in heating and towards said unheated position during a decrease in heating, said means for selectively absorbing absorbs heat at a greater rate in said unheated position than in said heated position, said elongate element and said source of electromagnetic radiation comprising a means for vibrating said element at a frequency which is at least partially dependant upon external stress on the elongate element.
Dependencies are inferred from the claim text.