Abstract: It is an object of the present invention to provide an ultrapure water producing apparatus with reduced problems resulting from impurities generated after replacement of unit apparatuses. A TOC-UV (1), a CP (2) and a UF film (3) are provided in this order from the upstream side of a pure water supply route. Ultrapure water flowing through the UF film (3) is supplied to a use point. A branch route branched from the pure water supply route is provided downstream of the UF film (3). A dissolved oxygen concentration meter (M1) is interposed in the branch route for measuring dissolved oxygen concentration in ultrapure water passed through the UF film (3). The branch route is connected to an oxidant decomposition unit (11). Oxidants included in ultrapure water flowing through the branch route are all converted into DO at the oxidant decomposition unit (11).

Abstract: It is an object of the present invention to provide an ultrapure water producing apparatus with reduced problems resulting from impurities generated after replacement of unit apparatuses.

Abstract: An apparatus for treating an organic waste gas has an oxidizing means for contacting the waste gas with an oxidizing agent to effect primary oxidation and form a primary oxidation product. An ultraviolet wave generator inadiates the primary reaction product with UV light in the near UV range to effect secondary oxidation of the primary reaction product.

Abstract: An air conditioning apparatus for a clean room has a filter for removing harmful chemicals provided in the return opening of an air-conditioner. In normal operation where there is no chemical leakage, circulating air in the clean room by-passes the filter. When chemicals and the like leak, the circulating air is caused to pass through the filter by operating shutters in order to remove the chemical mist and the like contained in the circulating air.

Abstract: A carrier cleaning and drying apparatus for cleaning and drying a wafer processing carrier has a cleaning tank for accommodating the carrier and a high-pressure injection nozzle disposed in an upper portion of the cleaning tank and for injecting a pressurized cleaning solution. This high-pressure injection nozzle is moved within a plane and the cleaning solution is injected at high pressure therefrom, thereby removing dust adhering to the inner and outer surfaces of the carrier by means of the force of injection. A supporting and rotating mechanism portion is also provided which, during cleaning of the carrier, swings the carrier at a predetermined angle, and, after cleaning, effects drying by spinning the carrier at high speed.

Abstract: An apparatus for counting particles attached to surfaces of a solid is disclosed which includes an external tank, an internal tank disposed within the external tank for hermetically accommodating a measuring liquid into which a sample having particles attached to the surfaces thereof is to be immersed, a driving mechanism for rotating the internal tank with respect to the external tank, sonic wave generators provided on the external tank for generating sonic waves having a plurality of different frequencies toward the internal tank, and a measuring mechanism connectable to the internal tank in a hermetic fashion for counting the number of particles in the measuring liquid removed from the sample by the sonic waves generated from the sonic wave generators.

Abstract: An object to be dried is cooled and then held within an atmosphere of a drying medium vapor, until the temperature of the surface of the object rises to the temperature of the vapor.

Abstract: A safety device for vessels of compressed gases is disclosed which comprises a cap enclosing the valve of the vessel, a port formed in the wall of the cap for passing a nozzle attached to the valve, a handling member for rotating the handle of the valve from outside of the cap, a purge gas introducing and exhausting ports formed in the wall of the cap, and a detector disposed in the middle of the exhausting pipe coupled to the purge gas exhausting port. The handling member comprises a shaft vertically extending through and slidably supported by the ceiling of the cap, a horizontal disk secured to the lower end of the shaft, and four circumferentially equally spaced vertically extending fingers fixedly secured to the circumferential portion of the lower surface of the disk, which disengagably engage with the grooves formed on the circumference of the handle.

Abstract: Disclosed is a liquid filter device for effectively eliminating impurities from liquid.Voltage is applied to liquid to break electrostatic coupling of liquid molecules and impurity molecules. The impurity molecules are electrostatically adsorbed by an electrode containing adsorbent having charges different in polarity from those of the impurity molecules.Voltage is applied to liquid to break electrostatic coupling of liquid molecules and impurity molecules. Adsorbent having charges different in polarity from those of the impurity molecules on its surface is provided between a pair of electrodes to electrostatically adsorb the impurity molecules. After the impurity molecules are electrostatically adsorbed, the liquid is filtrated by a filter.Voltage is applied to liquid to eliminate zeta potentials which are potential difference at electric double layers having charges different in polarity from those of impurity particles in interfaces between the impurity particles and the liquid.

Abstract: A device for continuously monitoring variations of the density of sodium ions borne by atmospheric air. A water tank is provided having a fixed volume with a top thereof opened to the atmosphere. Pure water, having a resistivity of at least 15 M.OMEGA..multidot.cm is continuously supplied into the tank and extracted therefrom at the same rate. The conductivity or resistivity of the extracted water is measured to determine the sodium ion concentration in the air. For small densities, a sodium ion electrode meter can be employed for measuring the sodium ion density.

Abstract: A device for measuring the absolute value of the density of salts in atmosphere, which comprises: an airtight water tank containing super pure water of a predetermined quantity; a means for bubbling a predetermined quantity of air in atmosphere for a predetermined time into the super pure water to make the salts in the air dissolve in the water; a means for exhausting the super pure water after the bubbling; and a sodium ion analyzer for measuring the density of sodium ions in the exhausted super pure water of a predetermined quantity.

Abstract: An SiO.sub.2 film doped with an impurity is formed on at least one portion of a surface of a semiconductor wafer. The wafer is selectively etched after a protective film for selective etching is disposed into a predetermined pattern on the SiO.sub.2 film. The impurity included in the SiO.sub.2 film can be diffused into the wafer to form a PN junction in the latter. Then the wafer is selectively etched until that surface of the wafer to which the PN junction is exposed is bevelled.