The 2B Technologies Model 202 Ozone Monitor™ and Model 202M Ozone Monitor™ (rack-mounted version) are designed to enable accurate measurements of atmospheric ozone in the mixing ratio range of 0-1000 ppbv (100000 ppbv in high concentration mode) based on the well established technique of absorption of light at 254 nm. The Ozone Monitor™ is light weight ( 2.1 kg.) and has a low power consumption, is simple to operate, does not require chemical reagents, and has a fast response time, is therefore well suited for applications such as:

Theory of Operation
Ozone is measured based on the attenuation of light passing through an absorption cell fitted with quartz windows. A low-pressure mercury lamp is located on one side of the absorption cell, and a photodiode  with built-in interference filter is located on the opposite side of the absorption cell. A pump draws sample air into the instrument, a solenoid valve alternately directs this air through an ozone scrubber and into the absorption cell. The intensity of light at the photodiode is measured in sample that has been scrubbed (Io) and air that has not been scrubbed (Hi). Ozone concentration is calculated from the measurements of Io and Hi according to the Beer-Lambert Law