Horiba Stec, Co., Ltd.

Hiroshi Takakura

Tadahiro Yasuda

Kotaro Takijiri

Kazuhiro Matsuura

Hiroyuki Ebi

Kenichi Oe

Yukimasa Furukawa

Daichi Kunita

Shohei Yamano

In order to eliminate influence of a noise voltage applied to a diaphragm of a capacitance type sensor, the capacitance type sensor includes: a detection capacitor formed of a diaphragm and a fixed electrode, the diaphragm being connected to a frame and deformed by receiving an external force; and a fixed capacitor connected in series with the detection capacitor, so that it is intended to detect a divided voltage applied to the detection capacitor by applying a voltage to the detection capacitor and the fixed capacitor, and further includes: a noise voltage generating part connected to the frame and adapted to generate a noise voltage caused in the frame; a noise voltage adding part adapted to add the noise voltage to the voltage applied to each of the capacitors; and a noise voltage subtraction part adapted to subtract the added noise voltage from a divided voltage of the detection capacitor.

Capacitance type sensor including detection and fixed capacitors

To achieve both response speed and accuracy required for a flow rate measuring device without sacrificing the simplicity and inexpensiveness of a PWM type D/A converter, the flow rate measuring device includes an analog conversion part adapted to convert a digital signal indicating a measured flow rate value to an analog signal. In addition, the analog conversion part includes: a PWM signal generating circuit that can output three or more specified voltages is configured to, on the basis of the measured flow rate value indicated by the digital signal, select two adjacent voltages, as well as on the basis of the measured flow rate value indicated by the digital signal, set a duty ratio to generate a PWM signal of which a high level and a low level are the two selected voltages, respectively; and a conversion circuit that smooths the PWM signal to convert to the analog signal.

Flow rate measuring device

In order to prevent an increase in size of a power source device in a power supply apparatus adapted to manage multiple flow rate controllers, the power supply apparatus is connected via cables to the multiple flow rate controllers adapted to control fluid flow rates, and manages operations of the flow rate controllers via the cables as well as supplying power to the flow rate controllers, respectively. In addition, the power supply apparatus is configured to include a power supply control part that shifts power supply start timings for at least some of the flow rate controllers.

Power supply apparatus of fluid control and measurement system

This invention is to improve procedures of maintenance of a fluid measurement system having a fluid measurement device and a control device. The fluid measurement system has a fluid measurement device and a control device to control the fluid measurement device, and the fluid measurement device comprises a fluid sensor and a related data store part configured to store fluid calculation related data for calculation of one or more fluid parameters with measurement data obtained by the fluid sensor, and the control device obtains the fluid calculation related data from the related data store part and calculates the one or more fluid parameters with the measurement data of the fluid sensor and the fluid calculation related data.

Fluid measurement system

The present invention is intended to inhibit a communication program from crashing in the case where a power source is turned off while writing or rewriting of a measurement control program from an external device is performed by a communication part, and includes: a first recording part for storing the communication program for controlling the communication part; a second recording part for storing a measurement control program for controlling the measurement control part; and a central processing unit. In this configuration, the communication program stored in the first recording part is configured to be unrewritable by the central processing unit and the measurement control program stored in the second recording part is configured to be rewritable by the central processing unit.

Fluid control device

A flow rate sensor is disclosed, comprising a flow rate calculation part that calculates a flow rate of a fluid based on an expression using X/Xthat satisfies an expression at least in a certain range of the flow rate when an output of a constant temperature control circuit corresponding to an upstream resistor is defined as V, an output of a constant temperature control circuit corresponding to a downstream resistor is defined as V, and the flow rate is defined as and the flow rate calculation part corrects the zero point output as being an output when the flow rate is zero by using a zero offset function (OFS) defined as a function of V+VX/X.

Flow rate sensor

A flow rate measuring device includes a fluid resistance member through which measurement target fluid flows; an upstream side pressure sensor configured to measure pressure on an upstream side of the fluid resistance member from a change of electrical resistance of a resistive element attached to a pressure sensitive surface onto which the target fluid is introduced, and also to measure a temperature of the pressure sensitive surface from a temperature-dependent change of the electrical resistance of the resistive element; a temperature sensor to measure a temperature of the target fluid flowing through the fluid resistance member; and a flow rate calculation part that calculates a flow rate of the target fluid based on the pressure measured by the upstream side pressure sensor, pressure-flow rate characteristics of the fluid resistance member, the upstream side pressure sensor temperature, and the target fluid temperature in the fluid resistance member.

Growing community of inventors

Kyoto, Japan

Hiroshi Takakura