Air Pollution Monitoring

The Models 202, 205 and 106-L are all well suited to ambient air measurements where ozone concentrations are typically in the range 0-100 ppb.  The EPA air quality standard currently is 75 ppb for as an 8-hour weighted average.  The Model 106-M and 106-H are designed for higher concentrations and not suited to this application.  The Model 202 continues to be our most popular ozone monitor and is widely used by the U.S. Forest Service, NOAA, the National Park Service and other government agencies.  The Model 205 Dual Beam Ozone offers slightly improved precision and better baseline stability than the Model 202. Both the Model 202 and Model 205 have been designated as Federal Equivalent Methods (FEMs) by the EPA, meaning that they may be used for ambient monitoring for enforcement of the Clean Air Act.  As discussed below, the Model 205 is preferred for fast measurements on aircraft and balloons.  For monitoring at fixed locations, and especially when the data are going to be averaged for 1 minute or longer, the Models 202 and 106-L provide more than adequate precision. The critical components of the Model 106-L are identical to those used in the Models 202 and 205.  The Model 106-L is built on a single PCB, making it less expensive to manufacture and more compact.  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 used for vertical profiling to altitudes up to 30 km using balloons 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.   In March 2010, the Model 202 became the only portable Federal Equivalent Method for ozone recognized by the EPA, with certification over the wide temperature range of 10 to 40 ^oC. For temperatures below 0 ^oC we offer a cold weather upgrade which includes a lamp heater and a rotary vane pump.  This option enables the instrument to be operated at temperatures as low as -20 ^oC.  For temperatures in the range 50-60 ^oC, you may simply disconnect the cell heater for more stable operation. 

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 ozone monitor commercially available.  The Model 202 and Model 106-L also are useful for measurements on aircraft and balloons but with less spatial resolution.

Indoor Air Quality (IAQ) Monitoring

Our Models 106-L, 202, 205 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 HMOS (heated metal oxide semiconductor sensors) are strongly affected by VOCs and are notorious for have 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 Model 202 Ozone Monitors.

Roadside Monitoring for NO, NO₂ and NO_x

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 ozone to form NO2. The traditional method of chemiluminescence is not well suited for roadside monitoring because of the large size and high power requirements. The Model 410 Ozone Monitor provides a highly portable approach to roadside monitoring of NO, and when used in combination with the Model 401 NO2 Converter (as used with chemiluminescence), NOx and NO2 are measured as well. Because of the great interest in measuring NO2, 2B Tech is currently developing a highly portable instrument for direct measurements of NO2.

Industrial Ozone

Ozone is now widely used for treatment of municipal water because of it greater effectiveness in killing pathogens such as bacteria and their spores and in deactivating viruses. Increasingly, ozone is being used in other industrial applications such as in HVAC systems for removing hydrocarbons and cigarette smoke from buildings, in the sterilization of medical instruments, soil and ground water remediation, preservation of fruits and vegetables during storage, processing of food products, ozone laundries, etc. These applications require ozone measurements ranging from per cent levels for the outputs of ozone generators to ppm levels for process streams and ppb levels for protecting against human exposure.

The Models 106-H (high ozone), 106-M (medium ozone) and 106-L (low ozone) were designed with differing optical bench lengths in order to allow ozone measurements spanning this range of more than eight orders of magnitude.  The Model 106-H is designed for measuring ozone at the per cent level produced by ozone generators.  The Model 106-H is a flow-through instrument with no pump and thus can be used in-line with ozone generators. The Model 106-M measures ozone in process streams up to 1000 ppm, and the 106-L measures ozone down to ~1 ppb..  The 106 series has a two-level relay switch for controlling ozone, sounding an alarm, or controlling other processes based on ozone concentration. This series of instruments has a 4-20 mA output in order to interface with common industrial recording instrumentation. The 106 series of instrument are available in standard enclosures, NEMA cases and as OEM versions with no case for those who want to include the instrument as part of a larger package.

Continuous ozone monitoring of personnel working with ozone is highly recommended for health and safety issues. The UV-based Personal Ozone Monitor or POM is ideal for accurate monitoring the exposure to ozone of individual workers. Ozone sensors such as electrochemical and HMOS sensors are too unreliable to provide the safety your workers deserve.

Detection of Surface Partial Discharges in Large Motors and Electrical Generators

The Model 202 Ozone Monitor has been successfully used for detecting surface partial discharges in electrical generators of hydroelectric power plans.  These discharges produce ozone by dissociation of oxygen molecules in air. For more details please see the paper by Louis Lépine of Hydro-Québec.  Early detection of partial discharges in electrical equipment can provide cost savings by preventing equipment failures. This application requires measurements at low ppb levels of ozone.  Please contact us for a quote for a complete setup for this application including Model 202 Ozone Monitor, Pelican case for storage, 10-hour external battery, sampling tube and other accessories.