Two turbopumped vacuum systems were each equipped with connections for up to three residual gas analyzers (RGAs) of different types. One system allowed comparisons of two commercial quadrupole RGAs with a time‐of‐flight (TOF) instrument of roughly similar performance; the other provided a comparison of a TOF‐RGA with a 5 cm radius magnetic sector‐field instrument. This TOF‐RGA was tested with flight path lengths of 29 and 82 cm. The magnetic RGA was tested in both accelerating‐voltage scan and magnetic‐scan variants, and with both first and second‐order direction focusing magnets. For each type of RGA, the adjustments essential for optimum performance were identified. For reliable quantitative data, it seems desirable to use some form of constant‐transmission mode for quadrupoles, magnetic scan or at least magnetic range change for sector‐field instruments, and modern transient recorder/averagers for TOF‐RGAs. It appears that minimum detectable partial pressures and resolving powers can be roughly similar for the three basic types of RGAs. Mass limits and maximum scan rates, on the other hand, are very different. We conclude that the ‘‘best’’ type of RGA is very much a function of the specific application.