Abstract: Provided is an apparatus for gas sampling from a harsh environment which comprises a chemically resistant plastic housing suitable for suspension in a confined spacial environment. The housing has apertures for inlet and outlet tubes by which sampled air is drawn into and then discharged from the housing. Included are two three way valves to control selective fluid communication with the environment, a gas sensor, a filter selectively remove contamination from the housing and prevent saturation of the gas sensor, a pump disposed within the housing to effect selective fluid flow through the gas sensor and filter, and a power source that is preferably batteries. The apparatus electronics are all integrated into an electronics module configured so as to communicate with an external readout in a remote location via several methods.