Abstract: The present invention is a method and system for detecting and measuring a tritium gas leak. The method comprises collecting and concentrating any tritium gas escaping from a container in a reservoir over a predetermined time period. The concentrated gas sample is then directed to at least one of two detectors, a highly sensitive ion chamber or a highly sensitive proportional counter. The activity of the gas sample, as indicated by one or both of the detectors, is related to the concentration time interval to provide a measurement of sample activity accumulated per unit time. Calibration with a known tritium leak allows the sample activity per unit time to be read as a leak rate.

Abstract: A method for electrically shorting a high current, low voltage, single, chloralkali, membrane, electrolytic cell of a certain configuration to permit first its removal from a system, comprised of a plurality of electrically series connected cells, for maintenance purposes and then its return to the system. The method comprises first employing an electrical jumper circuit, comprised of two sets of bus bars and a switch, to electrically short out two adjacent cells, one of which is to be removed from the system to undergo maintenance, and then to modify the circuit in situ to enable the shorted cell adjacent to the cell to be removed to be returned to the system almost immediately.

Abstract: An electrical shorting switch assembly for use with an electrolytic cell includes a plurality of parallel path electrical switches. One of the switches is an arcing switch which is designed to be a last-to-open and last-to-close switch of the assembly. A common rotatable operating shaft is used to actuate opening and closing of the electrical switches. The arc switch has separate linking means between the arc switch and the shaft which permits sequential operation of the arc switch relative to the main current-carrying switch or switches. The arc switch linking means in conjunction with the linking means for the current switches determine that the arc switch is the last to open and last to close.

Abstract: A low voltage, high continuous current DC switch assembly is provided having integral switch operating means with the switch and a resistance means which is fluid cooled. This switch assembly is particularly adapted to function as a shunt switch assembly connectable between generally parallel spaced apart electrical terminals which extend from or are connectable to an electrochemical cell. The switch assembly is modular in that a plurality can be assembled together as electrically parallel shunt paths.

Abstract: A hermetically sealed, partially evacuated switch is maintained at a non-oxidizing residual pressure of from about 10.sup.-1 to 10.sup.2 Torr by inclusion of selected hydrogen gettering metal hydride within the sealed switch envelope. The metal hydride is selected with a hydrogen equilibrium pressure at the switch operating temperature such that the pressure within the switch envelope is maintained in the desired range.

Abstract: An electrical shunting switch assembly for use with a high continuous D.C. current electrochemical cell system, for electrically shunting or by-passing a cell of the system to permit maintenance or replacement, and then permitting stepped or gradual current diversion back through the cell. This shunting switch assembly includes a plurality of electrically parallel switch modules which comprises a vacuum switch, a series connected resistance value and switch operating means for sequentially operating the switches for current diversion. The switch modules are disposed in a matrix arrangement connected between bus connectors which are connectable across the cell, with switch modules having a low resistance value in alternating adjacent relationship to switch modules having a high resistance value. The low resistance value modules permit high shunting efficiency. The higher resistance value modules provide the capability for stepped or gradual current diversion.

Abstract: A latching mechanism for a reciprocable actuating means which has a short linear reciprocable stroke between two opposed positions at opposed ends of the actuating stroke. The actuating means is designed for operating an electrical shunt switch useful with electrochemical cells. The latching mechanism operates to maintain the switch contacts in either the open contact or closed contact positions until a positive unlatching force is applied to permit movement of the contacts.

Abstract: An improved low voltage vacuum switch assembly and operating mechanism is disclosed for use as an electrically parallel shunting switch for an electrolytic cell. The improved switch assembly and operating mechanism includes linking means restraining guide means associated with a reciprocably movable linking means to restrain the linking means to essentially axial or reciprocable movement. This prevents any accidental switch contact closing as during installation.

Abstract: A vacuum switch assembly which is connectable as a shunting switch across the electrodes of an electrochemical cell, in which a plurality of electrical parallel current paths are provided through a plurality of parallel vacuum switches with separate electrical bus conductors extending from each switch contact. The vacuum switch layout is particularly adapted to permit bus conductor paths to the electrochemical cell which minimize stored induction energy which must be dissipated. The vacuum switch operating mechanism provides for approximately simultaneous switch operation with means for adjusting the individual switch openings. The switch assembly is compact and portable for correction to any one of the series cells in a plant.

Abstract: A low voltage, high continuous current dc vacuum switch has at least three internal contacts, including an electrically floating center contact and two movable end contacts. The multiple contacts provide electrically serial multiple arc paths so that the switch is operable to interrupt an arc at a dc arc voltage above the arc voltages at which an arc could otherwise be interrupted for a single arc path. Arc shield means are provided to prevent deposition of contact material on predetermined switch envelope internal surfaces.

Abstract: An improved low voltage, high current D.C. vacuum switch is provided by disposing an arcing shield annularly about the arcing contact area within the vacuum switch. The arcing shield prevents disposition of conductive contact material on the insulator body wall of the switch and also shields the flexible corrugated annular member which permits switch contact movement to open and close the switch. The arcing shield may be floating electrically, or connected to the electrically positive side of the switch contacts.

Abstract: A low voltage vacuum switch and operating mechanism is detailed which is readily used as a shorting switch arrangement in electrolytic cells between the high current carrying bus bars of the cell. The switch has a very low profile and axial contact travel distance and is opened and closed by a means which translates rotational motion to a generally axial contact movement via a cam and connecting member, with overtravel dished washer spring means provided to keep the contacts closed until a positive opening force is applied. The low voltage vacuum shorting switch is detailed with axially movable non-weld contacts. The switch has a compact, rugged design for use in low voltage, high current severe environment application. A pair of thin flexible annular members having annular corrugations formed therein permit axial movement of the contacts.

Abstract: A vacuum switch system for interrupting electrolytic cell circuits designed to operate at very high current, relatively low DC voltage. The DC voltage is above the minimum cathode drop potential for the vacuum switch contact material. The system includes plural parallel circuit paths, with one of the parallel circuit paths including at least two serially connected vacuum switches. The operating means for opening and closing all the switch contacts includes means responsive to the opening of the vacuum switches to simultaneously open the serially connected vacuum switches in the parallel path.

Abstract: A low voltage cell shorting vacuum switch is biased in the normally open position as well as being protected from the cell corrosive atmosphere by an electrically insulating, resilient elastomeric annular member.

Abstract: An electrochemical cell circuit has vacuum interrupter cell by-pass switches provided in order to prevent the impurities in the environment, caused by leakage from the electrochemical cells, from interfering with the switch operation.

Abstract: A high current shorting switch wherein relatively movable contacts are surrounded by a flexible bellows which forms a hermetically sealed chamber, within which the contacts are disposed. The contacts are supported on heavy current carrying supports which terminate in two large end plates. Insulated holes are formed in one of the end plates which engage rods extending from the other plate to provide guidance for relative movement of the two end plates. An annular ring is disposed within the flexible bellows to prevent or limit current flow through the flexible bellows. The flexible bellows are coated with a protective coating which substantially increase the life of the bellows. The contact surfaces are preferably formed from a material having good weld break characteristics, such as copper bismuth while the contact supports and the end plates are formed from a material which is a good electrical conductor, such as copper.

Abstract: An electrodeless discharge lamp system which is adaptable to an atomic absorption spectroscopy unit which is designed for hollow cathode discharge device operation.