Abstract: An apparatus is disclosed for propelling ink droplets from an ink jet nozzle which uses an expanding bubble as a driving mechanism. Unlike other thermal ink jet devices, the ink itself is not used to provide the driving bubble. Rather a two fluid system is disclosed whereby a flexible membrane is used to maintain separation between a working fluid and the ink. A bubble is thermally created in the working fluid which distends the membrane and causes ink on the other side of the membrane to be expelled from an ink jet orifice. The membrane is in direct physical contact with the surface of the bubble-generating resistor and a quantity of the working fluid lies between the resistor and the membrane in pockets created by roughening the surface of the membrane or by roughening the surface of the resistor; alternatively, pockets between the membrane and the resistor may be provided by particulates contained within the working fluid which provide local separations of the membrane and the resistor.

Abstract: An electron capture detector in which a thermionic source such as a filament provides electrons for the reaction in a source chamber having a port that connects to a detection chamber having a collector. Guard gas is introduced into the source chamber and sample gas into the detection chamber, and an exhaust port is provided in the detection chamber.

Abstract: This is an ion-producing source having a distinct chemical ionization configuration and a distinct electron impact configuration. In this source, a hollow chamber including an ion source and a source of sample molecules receives a hollow, slidable cylindrical member having a chemical ionization chamber within it. Orifices in the chamber and the cylindrical member connect the chemical ionization source chamber to the electron source and to the sample molecule source when the cylindrical member is pulled to one position. When the cylindrical member is pulled to another position, the slidable cylindrical member and the inside walls of the chamber define the ionization region to which the electron source and the sample molecule source are directly connected. By moving the cylindrical member, the ionization source can be changed from a chemical ionization source to an electron impact source.

Abstract: This is an ion-producing source having a distinct chemical ionization configuration and a distinct electron impact configuration. In this source, a hollow chamber including an ion source and a source of sample molecules receives a hollow, slidable cylindrical member having a chemical ionization chamber within it. Orifices in the chamber and the cylindrical member connect the chemical ionization source chamber to the electron source and to the sample molecule source when the cylindrical member is pulled to one position. When the cylindrical member is pulled to another position, the slidable cylindrical member and the inside walls of the chamber define the ionization region to which the electron source and the sample molecule source are directly connected. By moving the cylindrical member, the ionization source can be changed from a chemical ionization source to an electron impact source.