Quartz thermometer
AssigneeAsulab S.A.
InventorsRudolf Dinger, Jean-Georges Michel, Claude-Eric Leuenberger
Life of this patent
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Abstract
A quartz thermometer which emits a signal, the frequency of which is a substantially linear function of temperature. The thermometer comprises a quartz resonator provided with electrodes disposed on the margins of the upper and lower main surfaces, parallel to the length direction. The electrodes are supplied with electric current so as to cause the resonator to vibrate torsionally. The length of the resonator is substantially parallel to the X axis of the quartz crystal. An electronic circuit is responsive to the signal emitted by the resonator for producing an output representative of temperature.
Claims15
A quartz thermometer comprising:
- a resonator including at least one elongate element made from a quartz crystal, the length of said element being substantially parallel to the X axis of said quartz crystal, said element having two main surfaces which are substantially parallel to each other and to said length and delimited by edges, said main surfaces being perpendicular to an axis Z' which is inclined at an angle of between +30.degree. and -30.degree. with respect to the optical axis Z of said quartz crystal;
- at least one first group of four electrodes disposed on said element, parallel to said length, said electrodes being disposed on said two main surfaces of said element, adjacent the edges thereof;
- means for applying two different voltages to two of said electrodes that are disposed on the same main surface and to two of said electrodes that are located opposite each other on different main surfaces so as to cause said element to vibrate torsionally and to emit a signal, the frequency variations of which are a substantially linear function of temperature;
- means for supporting said element for said torsional vibration;
- and
- an electronic circuit for processing said signal emitted by said resonator, said circuit comprising:
- a reference frequency oscillator;
- and
- means for comparing the frequency of the signal emitted by said resonator and the signal emitted by said reference frequency oscillator and for producing an indication of the temperature to which said resonator is subjected from the difference between the frequencies of these signals.
A quartz thermometer comprising:
- a resonator including at least one elongate element made from a quartz crystal, the length of said element being substantially parallel to the X axis of said quartz crystal, said element having two main surfaces which are substantially parallel to each other and to said length and delimited by edges, said main surfaces being perpendicular to an axis Z' which is inclined with respect to the optical axis Z of said quartz crystal at an angle of between +30.degree. and +50.degree. or between -30.degree. and -50.degree., said element having two edges substantially parallel to said X axis;
- at least one first group of four electrodes disposed on said element, parallel to said length, each of said two edges and each main surface being provided with one electrode;
- means for applying a first voltage to the electrodes on the main surface and a second voltage to the electrodes on the edges so as to cause said element to vibrate torsionally and to emit a signal, the frequency variations of which are a substantially linear function of temperature;
- means for supporting said element for said torsional vibration;
- and
- an electronic circuit for processing said signal emitted by said resonator, said circuit comprising:
- a reference frequency oscillator;
- and
- means for comparing the frequency of the signal emitted by said resonator and the signal emitter by said reference frequency oscillator and for producing an indication of the temperature to which said resonator is subjected from the difference between the frequencies of these signals.
Dependencies are inferred from the claim text.