The new Model 211 Scrubberless Ozone Monitor uses the proven ultraviolet (UV) absorption method in combination with our patented (US Patent No. 8,395,776 B2) gas-phase scrubber technology to measure ozone virtually free of interferences. The instrument is ideally suited for measurements of ozone in heavily polluted air where interference is likely from particulates, mercury, or VOCs. The Model 211 combines the stability of our proven dual beam ozone monitors with our selective scrubber technology to provide accurate ozone measurements in the most polluted air. The enhanced optical path length of 30 cm provides a precision of better than 0.5 ppb for 10-second measurements, and the instrument can output new ozone measurements as often as every 2 seconds. The Model 211 now comes with SD flash card memory as a standard feature.