The invention is a single crystal force transducer in which the crystal is simultaneously resonated in two different modes having substantially the same frequency-temperature characteristics and different frequency-force characteristics. The difference in the change between the two resonant frequencies with a force applied to the crystal is therefore a temperature compensated signal indicative of the applied force. In the preferred embodiment the two resonant modes are anharmonic modes having a plurality of antinodes angularly disposed to each other.

A chip type oscillator which comprises two oscillator elements bonded to each other, and two protective plates bonded to the outer surfaces of the oscillator elements. The oscillator elements have lead electrodes which are provided on corner portions thereof and are connected with vibrating electrodes, and the protective plates have external electrodes which are provided on corner portions thereof. The external electrodes and the lead electrodes are independently connected with each other through conductive coatings provided on peripheral surfaces of the oscillator chip. Integrated load capacitors may also be formed on the oscillator chip. The two oscillator elements are so integrated with each other that it is possible to reduce the number of components as well as the packaging area and simplify the mounting operation.

The temperature of an environment is determined by measuring the acoustical response of a temperature sensitive two mode resonator placed in the environment. Two variable frequency signals are generated and applied to the resonator, and the two resonant frequencies of the resonator are determined. Frequency difference of the two frequencies is determined, and if the difference lies within a substantially uniform frequency range, the environment temperature is calculated from at least one of the frequencies. If the difference lies outside of the substantially uniform frequency range, then at least one of the two signals is spurious and no temperature calculation is made.

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.

This invention is directed to an AT-cut quartz resonator having two different resonant modes simultaneously occurring in which a generally rectangular polyhedron has first and second electrodes disposed on opposing faces, and having the width to height selected within the range of 8 to 25. The width is selected such that a thickness shear mode and flexure mode are simultaneously excitable and coupled together. The AT rotation angle is selected so that a first signal responsive to the coupled flexure mode and thickness shear mode has a substantially cubic frequency versus temperature response over a desired temperature range and a second signal responsive to the coupled flexure and thickness shear modes has a substantially linear frequency versus temperature response over the desired temperature range. This invention also contemplates an apparatus for generating an output signal having a stable frequency versus temperature characteristic utilizing such a resonator and further contemplates a method for generating such a temperature compensated output signal.