Abstract: A gas chromatograph controlled by a pair of microprocessors to have improved thermal maintenance and process operation. The microprocessors are operable to run independently of each other, with one microprocessor controlling heaters and other control devices and the other microprocessor running a graphical user interface. The two microprocessors are separated by a gas chromatograph assembly that includes one or more separation columns.

Abstract: A feed-through module for an analyzer, such as a gas chromatograph. The feed-through module is adapted for connection to a plurality of tubes and for conveying fluids between the tubes and an enclosed volume of a housing of the analyzer. The feed-through module includes a connection structure threadably secured to the housing and a feed plate removably mounted to the connection structure. A plurality of connectors are secured to the feed plate. The connection structure and the feed plate cooperate to define a plurality of internal flow networks. Each flow network is operable to convey one of the fluids between one of the connectors and the enclosed volume of the housing. Within each flow network, a stream of fluid is split and then recombined.

Abstract: A gas chromatograph for connection to a source of carrier gas and a source of a sample gas. The gas chromatograph includes a first bridge circuit with a sample sensor connected therein and a second bridge circuit with a reference sensor connected therein. The outputs of the bridge circuits are digitized and then subtracted from each other in a processor.

Abstract: A flow control device for a gas chromatograph is provided. The flow control device includes first and second valves each having alpha and beta operating states and a plurality of ports. In each of the first and second valves, the ports are associated to have alpha pairs of the ports and beta pairs of the ports. In the alpha operating state of each of the first and second valves, the ports in each of the alpha pairs are connected and the ports in each of the beta pairs are disconnected. In the beta operating state of each of the first and second valves, the ports in each of the beta pairs are connected and the ports in each of the alpha pairs are disconnected. The first and second valves are formed by a cylindrical manifold plate disposed between cylindrical first and second port plates. A first diaphragm is disposed between the first port plate and the manifold plate and a second diaphragm is disposed between the second port plate and the manifold plate.

Abstract: The present invention is directed to a gas chromatograph having a display screen. The gas chromatograph includes an explosion-proof housing and a transparent panel secured to the housing. The display screen is disposed in the housing and is visible through the transparent panel. A gas chromatograph (GC) assembly is disposed in the housing and includes a column for separating components of the gas and a detector for detecting the components of the gas. An electronics assembly is disposed in the housing and includes a microprocessor and memory. A graphical user interface (GUI) software application is stored in the memory and is executable by the microprocessor to display a plurality of windows on the display screen. The windows contain information about the operation of the gas chromatograph.

Abstract: The present invention is directed to a gas chromatograph (GC) module having a column assembly and a printed circuit board mounted to a valve assembly. A plurality of electronic devices are mounted to the circuit board. The electronic devices include non-volatile memory, pressure sensors and detector devices.

Abstract: A gas chromatograph controlled by a pair of microprocessors to have improved thermal maintenance and process operation. The microprocessors are operable to run independently of each other, with one microprocessor controlling heaters and other control devices and the other microprocessor running a graphical user interface. The two microprocessors are separated by a gas chromatograph assembly that includes one or more separation columns.

Abstract: A feed-through module for an analyzer, such as a gas chromatograph. The feed-through module is adapted for connection to a plurality of tubes and for conveying fluids between the tubes and an enclosed volume of a housing of the analyzer. The feed-through module includes a connection structure threadably secured to the housing and a feed plate removably mounted to the connection structure. A plurality of connectors are secured to the feed plate. The connection structure and the feed plate cooperate to define a plurality of internal flow networks. Each flow network is operable to convey one of the fluids between one of the connectors and the enclosed volume of the housing. Within each flow network, a stream of fluid is split and then recombined.

Abstract: A gas chromatograph for connection to a source of carrier gas and a source of a sample gas. The gas chromatograph includes a first bridge circuit with a sample sensor connected therein and a second bridge circuit with a reference sensor connected therein. The outputs of the bridge circuits are digitized and then subtracted from each other in a processor.

Abstract: A flow control device for a gas chromatograph is provided. The flow control device includes first and second valves each having alpha and beta operating states and a plurality of ports. In each of the first and second valves, the ports are associated to have alpha pairs of the ports and beta pairs of the ports. In the alpha operating state of each of the first and second valves, the ports in each of the alpha pairs are connected and the ports in each of the beta pairs are disconnected. In the beta operating state of each of the first and second valves, the ports in each of the beta pairs are connected and the ports in each of the alpha pairs are disconnected. The first and second valves are formed by a cylindrical manifold plate disposed between cylindrical first and second port plates. A first diaphragm is disposed between the first port plate and the manifold plate and a second diaphragm is disposed between the second port plate and the manifold plate.

Abstract: The present invention is directed to a gas chromatograph (GC) module having a column assembly and a printed circuit board mounted to a valve assembly. A plurality of electronic devices are mounted to the circuit board. The electronic devices include non-volatile memory, pressure sensors and detector devices.

Abstract: The present invention is directed to a gas chromatograph having a display screen. The gas chromatograph includes an explosion-proof housing and a transparent panel secured to the housing. The display screen is disposed in the housing and is visible through the transparent panel. A gas chromatograph (GC) assembly is disposed in the housing and includes a column for separating components of the gas and a detector for detecting the components of the gas. An electronics assembly is disposed in the housing and includes a microprocessor and memory. A graphical user interface (GUI) software application is stored in the memory and is executable by the microprocessor to display a plurality of windows on the display screen. The windows contain information about the operation of the gas chromatograph.