Abstract: A photoionization detector having an ionization chamber in which a sample gas can enter and be ionized by ionizing radiation that may be pulsed and with two spaced electrodes as a collector means and also having a plurality of annular electrodes regularly arranged in coaxial relationship between the two spaced electrodes to provide an electric field possessing a unifrom potential gradient for controlling the rate of migration of ions between the electrodes.

Abstract: A mixing valve for mixing a plurality of liquids comprises a number of valve units corresponding to the number of liquids to be mixed, each consisting of one inlet for liquid, one outlet and one ball valve having a valve ball and a valve seat.

Abstract: An apparatus and method are disclosed for an IV pump which can act also as a passive infusion controller. The apparatus has a disposable flow chamber with two pumping subchambers connected by a first collapsible passageway. A pump drive is used to operate the pumping subchambers and includes a first control valve for depressing the first collapsible passageway to control flow between the subchambers and an outlet control valve for depressing an outlet collapsible passageway to control flow of infusate out of the flow chamber. The flow chamber has a base surface and first and second caps, each cap being spaced apart from the base surface and having means for attachment to one of two moveable connector rods. The caps each act as one side of the first and second pumping subchambers, respectively, the base surface being the other side. A flexible wall is connected to the base surface and to each of the caps providing the subchamber volumes therebetween.

Abstract: In a system for analyzing a chemical sample by chromatographic separation of said sample into components a method and apparatus are provided for maximizing detector resolution and minimizing duration by maintaining the linear velocity of the mobile phase at a desired level by affecting the viscosity and density characteristics of the mobile phase as it passes through a restrictor by programming the restrictor temperature.

Abstract: A modular connector including mating male and female components providing electrical and pressure connection between the two components. The electrical connections comprise a telephone-type connector retained within molded apertures which also provide for a fluid flow between the mating components. The connector housing includes redundant molded sealing elements, disposed on surfaces of the male component of differing dimensions. The connector also features an overlapping member of one of the connector components providing an umbrella-like shield of the confronting surfaces to provide an environmentally resistant, reliable pressure tight seal.

Abstract: A burner for a flame photometric detector includes a stainless steel housing having a passage therethrough; a stainless steel burner tube extending through the passage and having a flame holder at one end; and at least one stainless steel inlet tube extending through the housing for admitting a support gas to the burner. The burner tube and inlet tube are brazed to the housing to form a unitary device having no sealing rings which can degrade and leak. A transfer line is connected to one end of the burner to conduct the material to be tested to the burner. The transfer line includes a fused silica tube surrounded by a stainless steel outer tube.

Abstract: A multi-element optical detector having a planar array of detector elements is focused at the focal plane of an optical spectrometer by placing the detector with the detecting surface of the array facing the optical spectrometer and being substantially perpendicular to the axis of the path of the light from the optical spectra to the focal plane. Relative movement is provided between the detector and the focal plane along said axis so that the detector array is placed at several different positions with respect to the focal plane. At each position the output values of the detector elements of the array are measured and the second difference of the output values is determined by the equation (-F1+2.times.F2-F3), where F1, F2, and F3 are the output values of three of the elements. The optical detector is placed at the position which provides the maximum value of the second difference, which is the position of the focal plane.