Abstract: A tube-shaped film, made of fluorine resin, has a fold-free, smooth, and uniform inner peripheral surface formed thereon by a surface treatment. An apparatus for treating the inner peripheral surface of the tube-shaped film includes a holding device for holding the tube-shaped film on the inner peripheral surface of a cylindrical body with a cylindrical configuration of the tube-shaped film maintained. A treatment device is inserted into the cylindrical body to treat the inner peripheral surface of the tube-shaped film held on the inner peripheral surface of the cylindrical body. The holding device and the treatment device make a uniform linear motion relative to each other and a uniform rotary motion relative to each other.

Abstract: Method and apparatus for measuring concentration of a solution use pathlength complementarily modulated cells comprising a sample cell and a reference cell arranged in parallel to each other and separated by a displacable separator window which is displaced parallelly in a direction of an optical axis of a measuring optical system thereby varying each of cell-length of sample and reference cells complementarily, detect transmitted intensities by the combined cells at different positions of the separator window while flowing a sample solution and a reference solution having a known concentration into the sample cell and reference cell, respectively, and calculate the concentration of the sample solution based on detected transmitted intensities, positions of the separator window at which transmitted intensities are detected and the known concentration of the reference solution.

Abstract: A centrifugal separator able to function as an agitator. A motor controlled by a control box drives a disk-like rotor. For agitation, the motor makes the rotor intermittently rotate, and for centrifuging, the motor makes the rotor constantly rotate. The rotor has a pair of pins which are extended in a tangential direction to the rotation of the rotor. A bucket for accommodating a sample container is freely swingably supported by a pair of pins. During the alternate repeat of the rotation and stopping of the rotor, the bucket with the sample container performs regular swing like a pendulum in the radial direction of the rotor. The rotation of the rotor and the swing of the sample container generate a smooth circular flow of the liquid content in the sample container.

Abstract: An automatic solution mixing apparatus is provided with a plurality of solution distributors located on opposite sides of a common base plate supported on a supporting block. The support block is movable in opposite directions. Pistons of the solution distributors are connected to the common base plate so that dual solution mixing operations can be performed by the solution distributors with a high degree of accuracy. Moreover, a stepping motor is utilized as a driving motor, and the operation of the stepping motor can be controlled by controlling the number of pulses supplied to the driving motor without using a rotaty encoder.

Abstract: The present invention relates to an apparatus of a fixed type for supplying filtered liquid which is able to filter liquid containing impurities of minute solid particles and then supply the filtered liquid while further filtering the same, said apparatus itself being of a fixed type, so designed that the liquid is repeatedly passed through a filter member provided within said apparatus for sufficient filtration, and at the same time, the liquid is filled in a movable container with rollers so as to be freely taken in or out of the apparatus in a completely purified condition, wherein the liquid in the movable container is transferred to fixed tanks, when the movable container is separated from the apparatus so as to be filled with fresh liquid, further to a discharge port through said filter member.