Abstract: A hydrogen generator includes at least two electrolytic cells, each comprising a membrane electrode assembly incorporating a solid polymer electrolyte. The membrane electrode of a first cell is exposed to water and the hydrogen produced in this cell contacts the cathode surfaces of the successive electrolytic cells, wherein any water entrained in or carried over with the hydrogen produced in the first cell is the only significant feedstock for the successive electrolytic cells. In some embodiments, the first and second cells share a common chamber enclosing the respective electrodes. Hydrogen generated by the first cell diffuses into an expanded polytetrafluoroethylene tube adjacent to the cathode. The tube discharges into a space abutting the cathode of the second cell.

Abstract: A demountable pellet is disclosed for use as an electrode contact assembly. The pellet comprises a base 1 upon which is mounted a plurality of electrodes 18, 19, 20 arranged in respective spaced parallel planes and having respective contacts 23, 24, 25 protruding from them. A closure 2 for the base 1 has a member 11, 12, 13 engaging at least one of the electrode contacts. In an unassembled condition of the pellet, with the closure 2 separate from the base 1 and each closure member disengaged from its respective electrode contact, the contacts 23, 24, 25 lie in respective spaced parallel planes. In the assembled condition of the pellet with each closure member engaging its respective electrode contact, at least one of the contacts 23, 24, 25 lies in a plane other than that in which it lay in the unassembled condition of the pellet.

Abstract: An ionization detector includes a third (fence) electrode (55) between the counter electrode (53) and the sensing electrode (54). The fence electrode (53) is maintained at or near the potential of the sensing electrode (54) and traps charge movement (electrolytic current) along the detector walls associated with condensation and/or contamination within the detector. In a photoionisation detector, the fence electrode is also adapted to trap photo-induced current originating from the cathode (53). Current drawn from the fence electrode (53) provides a measure of the degree of contamination or condensation within the detector and of lamp efficiency.

Abstract: The present invention provides a hydrogen collector and detector system for detecting emanating hydrogen from the test surface of materials, a hydrogen collector for use in such a system and a method for using the hydrogen collector in such a system. The present collector comprises a flexible plate, which has constructed on its receptor face raised grooves or high spots. These are presented approximately parallel to an approximately flat test surface or approximately tangential to a curved test surface, and form guiding channels along which hydrogen emanating from the test surface can be drawn and sent to an associated detector system. For use on a magnetizable surface, the present collector plate may comprise magnets by which it can firmly yet removably be attached to the test surface.