The new Model 211 Scrubberless Ozone Monitor uses the proven ultraviolet (UV) absorption method with an innovative gas-phase scrubber technology to measure ozone virtually free from interferences. In the reference mode, the instrument uses the reaction between ozone and nitric oxide (NO) to selectively remove ozone from the sample. This reaction is orders of magnitude faster than with any other ambient gas, resulting in the removal of only ozone and not potentially interfering compounds that absorb UV light. The instrument is ideally suited for measurements of ozone in heavily polluted air where interference is likely from particulates, mercury, or VOCs. The ozone monitor 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 gas-phase scrubber technology uses NO to quantitatively react with ozone and remove it from the sample. This reaction has long been used as a gas phase titration for the measurement of either NO or O₃. In the Scrubberless Ozone Monitor, a low concentration of NO is added to the sample to generate ozone-free, reference air. The light intensity is measured in the reference and sample modes, and the concentration of ozone is calculated directly from Beer's Law. Nitric oxide can be supplied from an external NO cylinder and will provide over a year of gas supply. Alternatively, nitric oxide can be generated inside the instrument using an optional photolytic NO generator and an external cylinder of nitrous oxide (N₂O), which is non-toxic, non-corrosive and relatively inexpensive.

Features

• Virtually interference-free measurement of ambient ozone

• Free of signal quenching interferences inherent to chemiluminescence methods

• DewLine™ for elimination of water vapor interference, a unique feature of 2B Tech instruments

• Inexpensive, simple, and robust instrument design in a 19” rack mount enclosure

• Touchscreen display

• Internal data logger and USB flash memory

• Dual beam optical bench with high precision

• Stable calibration (calibration suggested annually)

• Electronic sample and nitric oxide flow control

• Internal long-life sample pump

• Under evaluation as a Federal Equivalent Method (FEM)

• Convenient user interface, including remote operation via RS-232 communication

• Optional internal NO generator using non-toxic, noncorrosive nitrous oxide (N₂O)