Hitachi, Ltd.

Hitachi Instrument Engineering Co., Ltd.

Tamio Ishihara

Masao Fukunaga

Yutaka Sakurai

Hideo Enoki

Sadao Mori

Masami Sakamoto

Masatoshi Kanamaru

Ryo Miyake

Takao Terayama

Koji Saito

Katsutoshi Yamada

Masatsugu Arai

Akiomi Kohno

Kazuaki Yokoi

Ryoichi Nagumo

Yutaka Kaneko

Yuji Yoshitomi

Yuuji Yoshitomi

Masayuki Tamasaku

Kouji Saito

Tousaku Hattori

Takao Kobari

Shigeo Nishino

Souzo Fujimoto

Ryoichi Magumo

A water quality meter is composed of a plurality of water quality monitoring meters including analyzing units for analyzing water samples introduced from a water distribution pipe, each analyzing unit analyzing the water samples and a measuring cell, and a liquid introducing unit integrated with the analyzing units, which is composed of a single member in which a plurality of fluid flow paths for feeding various types of liquid including the water sample into the analyzing unit are formed. Furthermore, the cells and the plurality of three-dimensional fluid flow paths formed in the single member are fabricated by a micro-fabrication technique using photo-curing resin.

Water quality meter and water quality monitoring system

A water quality meter is composed of a plurality of analyzing units for analyzing water samples introduced from a water distribution pipe, each analyzing unit including a reagent mixing cell and a measuring cell, and a liquid introducing unit integrated with the analyzing units, which is composed of a single member in which a plurality of fluid flows paths for feeding various types of liquid including the water sample into the analyzing unit are formed. Furthermore, the cells and the plurality of three-dimensional fluid flow paths formed in the single member are fabricated by a micro-fabrication technique using photo-curing resin. In one embodiment, a photometer is situated in the flow path in at least one analyzing unit for measuring absorbency of the liquid. In another embodiment, a pair of electrodes, for measuring electric conductivity or pH, is disposed in a measurement flow path in at least one of the analyzing units.

A water quality meter is composed of a plurality of analyzing units for analyzing water samples introduced from a water distribution pipe, each analyzing unit including a reagent mixing cell and a measuring cell, and a liquid introducing unit integrated with the analyzing units, which is composed of a single member in which a plurality of fluid flow paths for feeding various types of liquid including the water sample into the analyzing unit are formed. Furthermore, the cells and the plurality of three-dimensional fluid flow paths formed in the single member are fabricated by a micro-fabrication technique using photo-curing resin.

Water quality meter and water monitoring system

A water quality management system for managing the water quality in a water supply network having water pipe lines running from the purification plant to consumers' faucets to maintain the water quality at the consumers at the terminals of the network at an appropriate level. The water quality monitors for measuring the quality of water in the pipe lines are installed in the small-pipe water distribution network branching from the water distribution main pipe network and running toward the consumers. The water distribution facility for improving the water quality is installed at the base point of the small-pipe water distribution network. The water quality in the small-pipe water distribution network is managed based on the signals from the water quality monitors.

Water quality management system

A capacitance type electromagnetic flowmeter whose output is relatively free from fluctuations caused by external vibrations has a flow tube supported in a casing member by means of members having elasticity and viscosity (e.g., O-rings). Magnetic parts such as coils and a core are fixed to the casing member so as to define a space therewith, and protective rings are kept liquid-tight with respect to the flow tube by O-rings interposed therebetween. The equivalent mass of the flowmeter section vibrating integrally with the flow tube is reduced to increase the resonance frequency. Further, since the flow tube is insulated from vibrations of the protective rings, the flow is less subject to vibrations, thereby decreasing fluctuations in output due to external vibrations.

Capacitance type electromagnetic flowmeter

An electromagnetic flow meter for industries includes a transducer and a signal processor provided separately from the transducer. The transducer having an exciting circuit, an amplifying and calculating part and a transmitting part outputs an analog flow rate signal and digital signals which are superimposed to the an analog flow rate signal to the signal processor. The analog signal sent to the signal processor is passed through the signal processor without receiving any signal processing and the digital signals are sent into the transducer or taken into the signal processor through alternating current coupling means. The data transmission is diagnosed by checking the conformity between the data stored in the signal sending part and the received data. Data set in a data setting part provided in the signal processor are sent to the transducer through a transmitting cable in which the flow rate data are also transmitted.

Electromagnetic flow meter

An electromagnetic flow meter comprises a ceramic measuring pipe formed into a straight cylinder through which fluid to be measured flows, electromagnetic field generating device disposed adjacent to a central portion of an outer surface of the central portion of the ceramic measuring pipe for generating an electromagnetic field into a radial direction of the ceramic measuring pipe, electrodes for detecting an electric potential generated in the fluid, a case which accommodates the ceramic measuring pipe, the electromagnetic field generating device and the electrodes, and sealing members which are disposed between inner surfaces of the flanges of the case and ends of outer circumference of the ceramic measuring pipe. The case has a length longer than that of the ceramic measuring pipe and flanges at both ends thereof. Inner diameters of the flanges are slightly larger than an outer diameter of the ceramic measuring pipe. Portions of the sealing members outwardly project over the end surfaces of the flanges of the case.

An electromagnetic flowmeter comprises a ceramic measuring tube through which fluid to be measured flows, a pair of electromagnetic coils disposed on the outer surface of the measuring tube in the central region thereof at diametrically opposite positions and generating a magnetic field in a direction perpendicular to the direction of flow of the fluid, a pair of measuring electrodes fixed to the outer surface of the measuring tube in the central region thereof at diametrically opposite positions and having electrode axes perpendicular to both the direction of flow of the fluid and the direction of the magnetic field, and a pair of metallic shields fixed to the outer surface of the measuring tube in surrounding relation to the measuring electrodes. A pair of the measuring electrodes and a pair of the metallic shields are fixed to the ceramic measuring tube by a reaction product due to an interface reaction with the ceramic measuring tube under heating.

Electromagnetic flowmeter and manufacture method of same

An electromagnetic flowmeter for measuring the flow rate of a fluid. The flowmeter has a measuring tube made of ceramics and defining a fluid passage therein for the fluid, electrodes having ends exposed to an interior of the measuring tube through holes which are formed in a wall of the measuring tube, a magnetic field generating device disposed around the electrodes, and a case encasing the measuring tube, the electrodes and the magnetic field generating means. A ratio t/R between a wall thickness t and a mean radius R of the measuring tube is determined such that stress generated in the measuring tube by the fluid in the measuring tube does not exceed the rupture stress of the measuring tube. The measuring tube can have flanges on both axial ends thereof, a radial height of the flange from an outer surface of the measuring tube is not greater than the wall thickness of the tube when the tube is made of Al.sub.2 O.sub.3 and not greater than a value three times as large as the tube wall thickness when the tube is made of Si.sub.3 N.sub.4. The electrodes may be made from Ni or an Ni alloy and are secured to the measuring tube by press-fitting into holes formed in the tube wall or by jointing. The electromagnetic flowmeter thus obtained exhibits high strength and reliability and high degree of gas-tightness in the tube portions around the electrodes.

Electromagnetic flowmeter

Plotter

An X-Y plotter is of the type which moves a non-perforated recording paper by drive rollers and pinch rollers. The outer surface of each of the drive rollers is formed with a cylindrical reference surface and with a plurality of minute projections of sharp quadrangular pyramidal shape distributed over the whole outer surface of the roller. These reference surface and minute projections are formed by machining in the entire circumferential or outer surface of the drive roller a plurality of trapezoidal grooves extending parallel and orthogonally to the axis of the drive roller.

X-Y plotter for non-perforated paper

An X-Y plotter disclosed is of the type which moves a recording paper with no perforation by drive rollers and pinch rollers. A plurality of sharp projections are arranged on the outer surface of each of the drive rollers such as to enable an exact feeding of the paper without any slippage. These projections are formed by cutting in the outer surface of each drive roller with V-grooves parallel and orthogonal to the shaft of the drive rollers.

X-Y plotter drive roller arrangement

A pen changing apparatus for a plotter is disclosed. A plurality of pens are mounted on a carriage in alignment with the axial direction of a shaft which is provided on the carriage as the sliding axis thereof. A guide shaft is fixed onto the carriage in the same direction as the shaft. A sliding lever for pressing any of the plurality of pens is provided on the guide shaft such as to be movable in the axial direction of the guide shaft and rotatable around the guide shaft. A solenoid rotates the sliding lever so as to press down a desired pen at the position where the sliding lever is located in resistance to a pen lifting spring or restore the pen to its original position by the urging force of the pen lifting spring. Leaf springs position the sliding lever over the desired pen and retain the same when the sliding lever is moved and stoppers are provided approximately at both end portions of the travelling range of the carriage such as to stop the sliding lever alone at the position over the desired pen at the time of moving the carriage.

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Katsuta, Japan

Tamio Ishihara