Abstract: A process for the continuous analysis of trace contaminants in a process gas of O.sub.2, N, Ar or H.sub.2. A sample of the process gas is passed through a plurality of analyzers with each dedicated to detect the presence of a predetermined trace contaminant and to provide an output signal corresponding to the level of trace impurity detected. A status signal is generated representative of preselected parameters of analyzer operation. The output and status signals are converted by a computer into data values. A rule based program provides a problem analysis to identify distinct problems based on the examination of the data values. The rule based program is executed by a separate command program which matches the problems identified by the rule based program with remedial actions to remedy erroneous conditions of analysis.