Abstract: A gas chromatograph includes a manifold having a plurality of gas conduits formed therein. A valve module includes a support, a first valve mounted to the support and having a plurality of ports, and a column coupled to the support and being in communication with a port in the first valve. The valve module is pluggably engagable with the manifold. A detector is coupled relative to the column to detect gasses expelled from the column.

Abstract: A gas chromatograph includes a manifold having a plurality of gas conduits formed therein. A valve module includes a support, a first valve mounted to the support and having a plurality of ports, and a column coupled to the support and being in communication with a port in the first valve. The valve module is pluggably engagable with the manifold. A detector is coupled relative to the column to detect gasses expelled from the column.

Abstract: A pH sensor has a core of an electrochemically inert insulating or semi-conductive material, and is coated with an electrically conductive, electrochemically sensitive coating. The preferred core is insulating and made of alumina, with a thin coating of iridium oxide deposited over at least a portion of the outer surface of the core. The coating is carried to a surface remote from the sensing surface and is used for making electrically conductive connections that lead to remote circuitry. The core is made in a form that can be supported and held in an insulating, electrochemically inert, deformable material that is sealed around the outer surface of the coating on the core to prevent leakage of chemicals being sensed. The body also permits sealing quite easily onto access ports on which the sensor housing is mounted. Various connections to the electrode coating can be made quite easily to provide for a unique sensor assembly.