Abstract: An apparatus and method for drying a wet gas. The apparatus has a chamber with an inlet port (14) for entry of the wet gas, and an outlet port (15) for exit of the dried sample of the wet gas. The chamber has a water-vapour permeable membrane (11) for separating at least a portion of wet gas from a drying agent adapted to operate at temperatures up to 100.degree. C. and comprises a perflurocarbon polymer with lithium sulphate groups covalently bonded to at least a portion of the carbon skeleton.

Abstract: Continuous production of ultra-pure helium and neon gases is achieved by utilizing the fact that these gases have the highest ionization and excitation potentials of all chemical substances. The helium/neon gas stream to be purified is excited by, for example, a corona discharge not only to directly ionize some of the impurities but also to produce noble gas ions and metastable atoms. These ions and metastables subsequently collide with and ionize impurities. A polarizing field is used to draw the impurity ions out of the main gas flow and into a subsidiary flow bled from the main flow. In a preferred embodiment, the polarizing field is established between a central rod-shaped anode (13) and a surrounding tubular cathode (10) through which the main gas flow passes. The cathode is made of a porous material so that positive impurity ions can be removed by the radial outwards flow of gas therethrough.

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: Apparatus for detecting gas in a sample gas in a carrier gas stream and including a windowless ionization detector having a pulsed power supply which is switchable at a rate which provides a pulse period shorter that the transit time of ions to be detected to the collector electrode of an ionization chamber of the detector. Switching allows any signal due to ion detection to be separated from background noise due to other effects in the chamber.

Abstract: The invention relates to apparatus for detecting a constituent gas in a gas flow. Means is provided for removing the constituent gas from a sample flow and directing this sample flow together with a reference flow containing the constituent gas through an equilibrator means wherein contaminants can be removed before the sample gas and the reference gas are compared in detector means, for example, an electron capture detector. The apparatus and method are also applicable to the detection of a liquid in a flow thereof.

Abstract: As oxygen is an electron absorber it is desirable, when monitoring an atmospheric flow for the presence of tracer materials capable of detection in an electron capture detector, to remove the oxygen from the flow to the detector. The invention introduces a hydrogen supply directly into the atmospheric flow to allow the hydrogen to combine catalytically with the oxygen content of the flow to form water or water vapor. The thus formed water or water vapor is extracted from the flow proceeding to the detector. The reaction can occur within a palladium or palladium alloy conduit forming a part of the flow path to the detector.

Abstract: A corona discharge device capable of use as an ionization detector or as a solute switch. Corona discharge pulses of short duration, preferably not exceeding one microsecond, can ionize a gas flow through the device. In the detector mode, electrons produced by the corona discharge can react with a compound to be detected in the gas flow. In the switching mode, the device converts a compound in the gas flow into a reaction product, and fluctuations in output signal of a detector connected to receive flow from the device correspond to the switching frequency of the device and are indicative of the compound in the gas flow.