Abstract: In a flow rate control valve comprising a fixed core made of a magnetic material provided with a coil arranged on a circumference thereof, a movable core and a valve body made of a magnetic material moved by an attraction by a magnetic force of said fixed core or a release from said magnetic force to open and close a valve seat and a movable member composed of a supporting spring, the fixed core is provided with a flowing conduit passing through an opening formed in a surface opposite to said movable member and the movable member is provided with a passage guiding a fluid, so that the total quantity of fluid can be smoothly flown without staying a part of the fluid.

Abstract: A control valve, in which a valve body opening and closing a valve mouth is driven by a strain force of a piezostack, characterized in that an upper fixed portion of said piezostack is supported by a ring-like tapered surface or a spherical surface and a lower movable portion of the piezostack is combined with a valve body through a spherical bearing.The strain output can be surely transmitted to said valve body by holding the piezostack so that no movement other than a strain resulting from the application of voltage may be produced.

Abstract: A valve body which is driven by a valve body-driving portion constructed from a piezoelectric stack to open and close a valve mouth. The piezoelectric stack consists of piezoelectric disc elements having a thickness of 0.1 to 0.5 mm and a diameter of 10 to 50 mm, whose upper surface and lower surface are both plated, and thin metallic plates each having a thickness of 0.05 to 0.2 mm and being high in electric conductance, are alternately laminated one between the piezoelectric elements by one (the number of piezoelectric elements laminated is 100 to 200). Every other one of the thin metallic plates are connected to a positive polar lead and the remaining plates are connected to a negative polar lead, and a voltage-applying lead wire is connected with each of the lead wires.

Abstract: The present invention relates to an apparatus for continuously measuring the concentration of oil in a water sample by the infra-red absorption method. The apparatus comprises a supplying device which supplies an oil-containing water sample and a supplying device which supplies a solvent for extracting the oil in the sample, each of said water sample and solvent being supplied in a controlled and continuous amount, an extractor connected to said supplying device having an agitator therein, which extractor receives said oil-containing water sample and solvent and serves to extract the oil component in the water sample with the solvent.