Abstract: Excitation electrodes are respectively affixed to central portions of both surfaces of a long plate-shaped AT-cut crystal resonator, the central portion starts a thickness shear oscillation in the length direction of the crystal resonator when an electric signal is applied to the central portion of the crystal resonator through the excitation electrodes. And, channel-shaped, half-circular-shaped, or trapezoid grooves in cross-section are respectively formed in the plate width direction on middle portions between the center portion and end portions of the crystal resonator. These grooves are formed so as to be symmetrical with respect to a thicknesswise central position of the crystal resonator through a well-known etching technique such as photo-etching and the like.

Abstract: Excitation electrodes are respectively affixed to central portions of both surfaces of a long plate-shaped AT-cut crystal resonator, the central portion starts a thickness shear oscillation in the length direction of the crystal resonator when an electric signal is applied to the central portion of the crystal resonator through the excitation electrodes. And, channel-shaped, half-circular-shaped, or trapezoid grooves in cross-section are respectively formed in the plate width direction on middle portions between the center portion and end portions of the crystal resonator. These grooves are formed so as to be symmetrical with respect to a thicknesswise central position of the crystal resonator through a well-known etching technique such as photo-etching and the like.

Abstract: Excitation electrodes are respectively affixed to central portions of both surfaces of a long plate-shaped AT-cut crystal resonator, the central portion starts a thickness shear oscillation in the length direction of the crystal resonator when an electric signal is applied to the central portion of the crystal resonator through the excitation electrodes. And, channel-shaped, half-circular-shaped, or trapezoid grooves in cross-section are respectively formed in the plate width direction on middle portions between the center portion and end portions of the crystal resonator. These grooves are formed so as to be symmetrical with respect to a thicknesswise central position of the crystal resonator through a well-known etching technique such as photo-etching and the like.

Abstract: A load sensor measuring a load by a change in oscillation frequency of a crystal (quartz) blank due to stress sensibility against thereof when a load is applied to opposing outer circumferential portions of the crystal blank. In the sensor, the crystal blank is formed in a shape such that when the load is applied, any mechanical deformation in a direction perpendicular to the plane of the blank is prevented. For example, the crystal blank is constituted by two regions, a vibrating portion having a relatively small thickness and a protective frame portion having a relatively large thickness. Alternatively, in a planar blank, a groove is formed so as to extend along the outer circumference of the blank. In the rectangular blank, the frame portion or groove is preferably arranged along sides of the blank parallel with a direction in which the load is applied.

Abstract: A device used with a conveyer weigher for automatically correcting dynamic weight signals indicative of the weights of articles successively fed to the weighing conveyer of the weigher at constant intervals, wherein the weight signal of each article is influenced by the "aftereffect" of that of the preceding article, which can automatically change the rate of correction when any article drops out from a regular interval feed line, thereby obtaining the true static weight of each article at any time.

Abstract: A weighing system, including a plurality of conveyer-type continuous weighing machines each having an analog weighing unit and a digital measurement processing unit, and a single common analog-to-digital convertor operated in time division fashion.