Azbil Corporation

Yamatake Corporation

Yasuhide Yoshikawa

Takashi Masuda

Toru Yamaguchi

Yoshiyuki Ishikura

Raita Mori

Takuya Ishihara

Masashi Sekine

Hidenobu Tochigi

Keisuke Obara

Kimihiro Sato

Jun Ichihara

Takayoshi Kawazu

Mayuka Sakai

Satoshi Kamiya

Mitsuhiko Nagata

Vacuum gauge

An improved diaphragm vacuum gauge including a sensor chip that includes a first electrode provided on a base and a second electrode provided on a diaphragm so as to face the first electrode, the diaphragm and the base being disposed with a gap therebetween, and in which a distance between the first electrode and the second electrode changes in accordance with displacement of the diaphragm caused by pressure of a measurement target medium. The diaphragm vacuum gauge further includes an operational amplifier that converts a current output from the first electrode to a voltage and amplifies the voltage, and a coaxial cable that connects the first electrode and the operational amplifier with each other. Further, the first electrode is connected to a virtual ground of the operational amplifier by a core wire of the coaxial cable.

Diaphragm vacuum gauge with decreased parasitic capacitance

An improved diaphragm vacuum gauge includes a pressure receiving unit having an electrical property that changes in accordance with displacement of a diaphragm caused by pressure of a measurement target medium; a heater that heats the pressure receiving unit; a temperature sensor that measures a temperature of the pressure receiving unit; a pressure measurement unit that converts a change in the electrical property of the pressure receiving unit to a pressure measurement value; a storage unit that stores a plurality of heating temperature settings; a heating temperature setting unit that selects one heating temperature setting from among the plurality of heating temperature settings in accordance with a digital input signal that is externally input; and a controller that controls power supply to the heater based on the temperature measured by the temperature sensor and the heating temperature setting selected by the heating temperature setting unit.

Adjustable self-heating diaphragm vacuum gauge

In a capacitance type pressure sensor () including capacitance detecting portions formed in opposed regions in a capacitance chamber which is at least partially formed of a diaphragm, the capacitance detecting portions being a pressure-sensitive capacitance detecting portion () formed in a region of the diaphragm having large sensitivity with respect to a pressure and a reference capacitance detecting portion () formed in a region of the diaphragm having small sensitivity with respect to a pressure, there is provided the capacitance type pressure sensor which is entirely small in size and superior in reliability by independently detecting a signal output value of the reference capacitance detecting portion ().

Capacitive pressure sensor

Disclosed is an intrinsically safe sensor signal processing circuit, permitting lower cost installation and eliminating potential hazard. In the combination of a sensor which measures physical value as process variables in hazardous environment and a safety barrier which is mounted in non-hazardous environment, an intrinsically safe sensor signal processing circuit features the safety barrier for case of mounting, wherein current limiting resistances are connected in series with the sensor and these resistances are also connected to either an output or an inverting input of OP Amps that are considered as a driver or a feeder of the sensor signal. The safety barrier can adopt blocking capacitors instead of said current limiting resistors.

Intrinsically safe sensor signal processing circuit

A sensor signal processing apparatus includes a sensor section, power supply section, switching section, and CPU. The characteristics of the sensor section change in accordance with a change in physical quantity to be measured. The power supply section supplies powers of two systems having different polarities to the sensor section. The switching section is connected between the power supply section and the sensor section to switch combinations of powers of the two systems from the power supply section while preventing mixing of powers of the two systems. The CPU obtains the ratio between the differences between a plurality of signals output from the sensor section for every switching operation of the switching section.

Sensor signal processing apparatus

Growing community of inventors

Tokyo, Japan

Yasuhide Yoshikawa