Hitachi, Ltd.

The Tokyo Electric Power Company, Incorporated

Sadao Mori

Masao Fukunaga

Toshio Akatsu

Hideo Enoki

Tamio Ishihara

Masatoshi Kanamaru

Ryo Miyake

Takao Terayama

Koji Saito

Katsutoshi Yamada

Eiji Takahashi

Tokio Yamagiwa

Hiroyuki Kawamoto

Yoshiteru Miyatake

Yasumasa Ishida

Motoi Wada

Hisamitu Hatoh

Chuuichi Miyazaki

Chyuuichi Miyazaki

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

Light from a light source is fed to a sensing probe through a polarization plane-reserving fiber, and is split into two light beams, that is, a reference beam and a measurement beam. The reference beam is passed through a reference medium, and the measurement beam is passed through a pressure-sensitive medium, which may be in the form of gas. Then, the reference beam and the measurement beam are fed to a light-receiving portion via the polarization plane-reserving fiber, and are converted into electrical signals. The electrical signals are inputted into a signal processing portion, and the optical path length difference between the reference and measurement beams, passed through their respective mediums, is determined, and the pressure of the pressure-sensitive medium is detected from this optical path length difference.

Optical pressure detection method and apparatus

A physical quantity measuring apparatus in which the measurement range of the physical quantity such as displacement, pressure or the like can be widened. Laser beams different in wavelength are radiated through an optical fiber onto a diaphragm and the light reflected on the diaphragm and the light reflected on a reference face opposite to the diaphragm are returned to the optical fiber so that the distance between the reference face and the diaphragm which is transformed, and hence a pressure difference, is measured by a light interference method. The quantity of displacement of the diaphragm is measured optically by using laser beams different in wavelength from each other so that it is possible to make the measurement accuracy high and to effect measurement in a wide range with respect to a physical quantity such as displacement, pressure, or the like, without being influenced by a change in characteristic of the optical fiber.

Physical quantity measurement apparatus and instrument therefor

There are disclosed an automatic focusing apparatus and an automatic focusing method for an optical disk apparatus. The present automatic focusing apparatus comprises a light source for outputting an optical beam to be focused; a focusing optical system for focusing the optical beam to be focused onto a desired position by using a photorefractive crystal having a lens effect; a device for forming a refractive-index distribution forming beam having a predetermined intensity distribution and outputting the beam onto the photorefractive crystal to generate a lens effect in the photorefractive crystal; a control beam outputting device for outputting a control beam onto the photorefractive crystal to control the lens effect caused by the refractive-index distribution generated in the photorefractive crystal; and a device for controlling the control beam outputting device. Focus adjustment is thus made without moving the lens.

Automatic focusing apparatus and method includes a photorefractive

A positional measuring laser interferometer splits a laser beam into a measuring beam and a correcting beam. Each of these beams is further split into a measurement beam and a reference beam. The reference beams travel along a fixed length path of fixed optical properties. Each of the measurement beams travels along respective optical paths in air adjacent each other so that they travel in air having substantially the same changing optical properties, such as the fraction index, preferably with the paths differing in length by a fixed amount regardless of the movement of the object to be measured. The reference beam and measurement beam, for each of the measuring and correcting beams, form an interference pattern that is detected to produce respective outputs correlated to positional information of the object and subjected to positional error due to changing refraction index of air. These two information signals are combined, preferably with a reference refraction index and a reference object position, to obtain a positional information signal of the object that is independent of varying optical characteristics of air. The solid/air interface surface for the interferometer, with respect to the measurement beams, is fixed in position independently of thermal or like expansion of the interferometer by an adjacent abutment surface spring biased into a fixed base abutment surface, which abutment surfaces are generally coplanar with the solid/air interface surface and perpendicular to the path of the measurement beams in air.

Laser gauge interferometer and locating method using the same

Disclosed is a method and apparatus which can detect progress of degradation of a sodium-sulfur cell and predict possibility of final breakdown of the cell in a very near future before such a final breakdown of the cell actually occurs. The method and apparatus for diagnosing the presence or absence of an abnormal state in the sodium-sulfur cell, containing a porous electrical conductive material impregnated with molten sulfur or sodium polysulfide as its positive electrode reactant and containing sodium as its negative electrode reactant, comprises observing the operating voltage of the cell during charging and discharging so as to detect occurrence of a minute ripple in the operating voltage, and, when the amplitude of the ripple and the frequency of occurrence of the ripple increases as a result of repeated cycles of charging and discharging, deciding that degradation of the cell has progressed to an extent that final breakdown of the cell will occur in a very near future.

Method and apparatus for diagnosing abnormal state of sodium

A light beam is projected on a reference plane and an object to-be-measured, a phase difference between reflected lights from them is changed by a phase shifter, a drive voltage for causing the change of the phase difference is applied to the phase shifter, a magnitude of phase shift of the phase of the reflected lights is detected by a phase shift detector on the basis of the drive voltage at a point of time at which the change of the phase difference of the reflected lights has been compensated, and an up pulse or down pulse is generated by an up-down pulse generator upon detecting a discontinuous change in the magnitude of phase shift attributed to the displacement of the object to-be-measured, while a pulse is generated by another pulse generator upon sensing a change in brightness of an interference signal of the reflected lights attributed to the displacement of the object to-be-measured. Besides, a mode selecting circuit supplies the output of the up-down pulse generator to a counter when a displacement speed of the object to-be-measured is lower than a reference speed, whereas it supplies the output of the other pulse generator to the counter when the displacement speed is higher than the reference speed. The displacement of the object to-be-measured is measured by utilizing an output of the counter.

Method of and apparatus for optically measuring displacement

The magnitude of displacement of an object to-be-measured is measured by projecting light beams on the object to-be-measured and a reference plane and utilizing the interference of lights reflected therefrom. The reflected lights from the object to-be-measured and the reference plane have their phase difference changed cyclically and forcibly. The discontinuous change of the magnitude of phase shift at the moment at which the phase difference of the two reflected lights caused by the displacement of the object to-be-measured has been compensated, and the magnitude of displacement of the object to-be-measured is found from the counted result of the discontinuous changes and the magnitude of phase shift at the moment at which the phase difference has been compensated.

Growing community of inventors

Tsuchiura, Japan

Sadao Mori