Abstract: A testing module for use with a gas detector, includes a plurality of gas inlets and outlets, each outlet being in fluid connection with one of the inlets. Each of the outlets is adapted to mate with and form a fluid connection with one of the inlets of a second like testing module. Gases can then flow from the outlets of the testing module into the inlets of the second like testing module. A gas container module for use with a gas container, includes a plurality of gas inlets and outlets, each inlet being in fluid connection with one of the outlets. Each of the inlets is adapted to mate with and form a fluid connection with one of a the outlets on a second like gas container module. Gases can then flow from the outlets of the second like gas container module into the inlets of the gas container module.

Abstract: A photoionization detector includes a housing, electrical contacts within the housing and an easily removable and replaceable photoionization chamber within the housing. The photoionization chamber includes a cathodic electrode and an anodic electrode which may be coated with a thin layer of material. The photoionization chamber and the associated cathodic electrode and anodic electrode are removable from within the housing as a unit. The photoionization chamber makes electrical connection with the contacts when seated within the housing regardless of the orientation of the photoionization chamber about an axis.