Abstract: A measuring apparatus for measuring the number and size of impurities such as dust and bacteria in super-pure water includes a sealed container; a sample supply line which sealingly interconnects a source of super-pure water with the sealed container and supplies a sample mixture of super-pure water and electrolyte to the sealed container; an overflow pipe which sealingly connects with the side of the sealed container; a negative electrode which extends into the sample mixture in the sealed container; a hollow sensor which extends into the sample mixture in the sealed container, the hollow sensor containing a positive electrode surrounded by electrolyte and having a small hole at its lower end; and a detecting circuit connected to said negative and positive electrodes for supplying a certain DC current therebetween and detecting voltage pulses caused by impurities passing through the small hole into the hollow sensor.

Abstract: An apparatus for adjusting concentration of a solution comprises a plurality of semipermeable membrane tubes located within a container, a liquid A supply pipe connected to the container and communicating with the interior of said semipermeable membrane tubes and a liquid B supply pipe connected to said container to communicate with the exterior of the tubes.

Abstract: A liquid chromatograph includes a solvent tank, a pump, a sample injection element, a column, a detector, conduits for successively interconnecting these elements, and a flow controller which is connected between the pump and the detector and in parallel with the column.

Abstract: A degassifying apparatus for removing air or other dissolved gas from liquid comprises a degassifying tank placed under at least a partial vacuum. The apparatus also includes a coiled tube having a plurality of turns in a generally spiral configuration which is positioned within the tank. Spacer elements are positioned between adjacent coiled turns of the tube and/or between the tube and an inner wall of the tank to eliminate contact between the tube and the tank and to thereby maximize the total surface area of the tube which is exposed to the decompressed atmosphere within the tank. This provides a highly desirable and advantageous degassifying effect to the liquid being conducted through the tube.

Abstract: Disclosed herein is a high-sensitivity differential refractometer which is characterized by having a light source disposed outside a housing, a reflecting mirror attached at the end portion thereof to a reflecting mirror-supporting plate connected with the end of a movable plate, said movable plate being so constructed as to rotate around a vertical axis and permit free change of the angle formed between said reflecting mirror-supporting plate and the movable plate, a twisting member disposed inside a lead-in tube and said lead-in tube fastened to a removable case and built in a metallic block inside the housing.