Air Pollution Monitoring
2B Tech's highly portable ozone and NOx monitors have long been used for ambient air monitoring applications. All five of our ozone monitors have been designated by the US Environmental Protection Agency (EPA) as Federal Equivalent Methods (FEMs), and our new Model 405 nm NO2/NO/NOx Monitor is pending FEM approval. Because of their small size and weight and very low power requirements, 2B Tech instruments are widely used in remote locations and where deployment of conventional air monitoring instruments is not possible. Agencies operating networks of 2B Tech instruments include the National Forest Service, National Park Service, NOAA and British Antarctic Survey. Those deployments have made use primarily of our original Model 202 and our Model 205 Dual Beam Ozone Monitor, which offers slightly improved precision and better baseline stability. In many cases, the ozone monitor is paired with one of our Model 306 Ozone Calibration Sources for daily zero and span calibration checks in the field. Although originally designed for ambient monitoring in industrial environments, our Model 106-L is a more modern redesign of the Model 202 with an emphasis on manufacturability. The Model 106-L is built on a single printed circuit board (PCB) and will soon have a touchscreen user interface. An OEM version without an instrument case is available as the OEM-106-L for those customers who want to repackage the instrument for incorporation into other systems.
Ozone Monitoring in Extreme Environments
2B Technologies instruments were designed from the beginning to deal with harsh environments. The first use of the Model 202, for example, was vertical profiling to high altitudes using kites, balloons and light aircraft where both temperature and pressure have huge variations over short time scales. Since then, our instruments have been demonstrated to produce long-term, stable and precise measurements in extreme environments ranging from measurements throughout the Antarctic winter by the British Antarctic Survey to summer measurements in the hot desert sun of Death Valley by the Desert Research Institute. For temperatures below 0°C we offer a cold weather upgrade, which includes a lamp heater and a low temperature pump. This option enables the instrument to be operated at temperatures as low as -20°C. A customized Model 202 was developed for the O-Buoy project in which ozone measurements are made through the winter on buoys deployed in the Arctic Ocean.
Measurements from Aircraft and Balloons
The Model 205 Dual Beam Ozone Monitor was designed specifically for aircraft measurements and vertical profiling using kites and balloons, where high spatial resolution requires a fast response time. The Model 205 may be thought of as two Model 202 Ozone monitors working 90° out of phase. One detection cell is measuring sample air while the other is measuring ozone-scrubbed air. The roles of the two cells are switched every two seconds. This allows reporting of new measurements every 2 seconds with a 100% response time of 4 seconds. The Model 205 is the fastest commercially available ozone monitor based on UV absorbance. The Model 202 and Model 106-L also are useful for measurements on aircraft and balloons but with less spatial resolution, and our new Model 405 nm NO2/NO/NOx Monitor may be used for direct measurements of NOx species aboard aircraft.
Indoor Air Quality Monitoring
Our Models 106-L, 202, 205, 211 and POM are all well suited for Indoor Air Quality monitoring, and because these instruments are based on UV absorbance, they provide much more accurate measurements than do electrochemical or solid-state sensors. Electrochemical sensors respond to a wide range of oxidants such as hydrogen peroxide and reductants such as sulfur dioxide. Solid state sensors such as HMOS (heated metal oxide semiconductor sensors) are strongly affected by VOCs and are notorious for having large drifts in sensitivity. The current US OSHA occupational exposure limit for ozone is 100 ppb based on an eight-hour average. In addition to the US and Europe, our ozone monitors are widely used in Asian countries. For example, China's Guangxi Province recently purchased and installed 92 of the 2B Technologies Model 202 Ozone Monitors.
Roadside Monitoring for NO, NO2 and NOx
There has been great interest recently in the exposure of individuals to air pollutants, especially NO2, along roadsides. Most of the NOx emitted by automobiles is in the form of NO, but a small fraction is emitted as the much more toxic species NO2, and NO reacts with ambient ozone to form NO2. The traditional method of chemiluminescence is not well suited for roadside monitoring because of the large instrument size and high power consumption, as well as the requirement to measure NO2 by use of a molydenum catalytic converter with poor selectivity and variable conversion efficiency. The Model 405 nm NO2/NO/NOx Monitor provides a new direct method for roadside monitoring of both NO2 and NO. The Model 405 nm is based on measurement of NO2 by direct absorbance at 405 nm using an ~2 m folded path. NO is measured by modulating the addition of ozone to convert NO to NO2 with ~100% efficiency. The Model 405 nm has the advantage of providing fast measurements of both NO2 and NO, whereas the recently developed Cavity Attenuated Phase Shift (CAPS) instruments typically measure only NO2. Approval as a Federal Equivalent Method (FEM) is pending for the Model 405 nm.