Temperature sensitive transducer with a resonant bimetal disk
AssigneeTechnar Incorporated
InventorsLon E. Bell, William P. Gruber
Life of this patent
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Abstract
A temperature sensing transducer has a mechanically vibrating member whose rigidity varies with temperature, changing the resonant frequency. An output signal is generated having a frequency controlled by the vibrating member. The rigidity is caused to vary with temperature by making the vibrating member from a material whose modulus of elasticity is sensitive to temperature changes in the desired measurement range. Also by making the vibrating member of a bimetal shaped as a frusto-conical disk, the rigidity of the disk changes with temperature due to internal strains.
Claims6
A temperature sensitive transducer comprising:
- a vibrating member comprising a bimetal disk having a resonant mode of vibration, the vibrating bimetal disk having a stiffness that changes over a wide range with small changes in temperature, electrical drive means for sustaining vibration of said bimetal disk in its resonant mode, and means for generating a periodic output signal tuned to the frequency of the vibrating bimetal disk.
A temperature sensing apparatus comprising:
- a thermally conductive base, a bimetallic frusto-conical shaped vibrating disk supported from and in thermally conductive contact with the base at a free nodal point, the vibrating disk having a stiffness that changes widely with small changes in temperature, means for vibrating the disk in a resonant frequency mode, and means for generating a digital output indicative of the vibrating frequency of said disk.
Dependencies are inferred from the claim text.