Yokogawa Electric Corporation

Yokogawa Hokushin Electric Corp.

Kinji Harada

Kyoichi Ikeda

Takashi Kobayashi

Takashi Yoshida

Tetsuya Watanabe

Tadashi Nishikawa

Hideki Kuwayama

Katsumi Isozaki

Motoyoshi Ando

A vibrating type transducer wherein an H-shaped vibrator, formed integrally with a silicon substrate and having a hollow chamber provided therearound, is kept self oscillating at its natural resonance frequency together with an amplifier. A physical quantity, such as force, pressure, differential pressure, or the like, which is applied to the silicon substrate is detected by a change in the natural frequency arising at the vibrator corresponding to the physical quantity. The invention also includes a method for manufacturing such transducer using a semiconductor technique, including steps for keeping a vacuum internally in the hollow chamber, imparting an initial tension to the vibrator, and then operating the amplifier to have stable self oscillation.

Vibrating type transducer

Process for manufacturing a vibrating type transducer

Oscillator using H-shaped single crystal silicon vibrator

A pressure gauge for determining the pressure applied to a cylindrical vibrator by measuring the resonance frequency of the vibrator. The vibrator comprises a thin-wall cylindrical portion, a thick wall cylindrical portion extending from one end of the thin wall cylindrical portion and a thick wall end portion joined to the end of the thin wall cylindrical portion. The thin wall cylindrical portion is installed within a cover, to which the thick wall end portion is securely attached. The inventive vibrator type pressure gauge produces greater accuracy and reliability while also being resistant to external vibrations and pressures.

Cylindrical vibrator type pressure transducer

A vibration type density meter includes a mechanical oscillator or resonator having a resonance frequency variable with the density of a specimen fluid around the oscillator. The resonator is of a cylindrical configuration with flanges at the ends thereof, at least one of the ends being open for introducing specimen fluid into the resonator. The meter also includes means for exciting the resonator, means for detecting oscillations of the cylindrical resonator, a cover coupled to the flanges of the resonator in surrounding relation to the latter, and circuit means for processing a frequency signal from the oscillation detecting means, and by arithmetic operations derive and display the density of the specimen fluid being measured.

Vibration type density meter

Growing community of inventors

Tokyo, Japan

Kinji Harada