Scrubberless Ozone Monitor | 2.B Tech
The Model 211 Scrubberless Ozone Monitor uses the method of ultraviolet (UV) absorption in combination
with our patented (US Pate'bdnt No. 8,395,776 B2) gas-phase scrubber technology to
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 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 animation above illustrates the principle of a gas-phase NO scrubber for a single-beam instrument. A small amount (~5 ppm) of nitric oxide (NO; blue) is pulsed into the air flow every 2 seconds to destroy the ozone and produce nitrogen dioxide (NO2; green) which doesn't absorb the UV light. When ozone (red) is present the signal at the photodiode is reduced due to ozone absorbing the UV light. When ozone is destroyed by the NO, the signal increases. The difference in measured light intensities is proportional to the ozone concentration. Because the potentially interfering species (benzene, toluene, xylenes, aldehydes, mercury, etc.; colored yellow) are always present and not modulated by NO, they do not contribute to the signal difference and thus do not interfere with the ozone measurement.
An Application Note gives one example of the use of the Model 211 in research; in this case it was used in a study of wintertime air quality in Utah. The 211's ability to measure ozone without interferences from VOCs made it uniquely suited to this study. Please searchthe application note in "download"
Features :
- Interference-free measurement of ambient ozone
- 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
- Internal data logger
- SD flash memory for virtually unlimited portable data storage
- Dual beam, long path (30 cm) optical bench with high precision (< 0.5 ppb)
- NIST-traceable calibration (calibration suggested annually)
- Internal long-life sample pump (20,000 hours)
- EPA Federal Equivalent Method (FEM) for compliance monitoring (EQOA–0514–215)
- Candidate to become a new EPA Federal Reference Method (FRM)
- Convenient user interface, including remote operation via RS-232 communication
- Internal NO generator from non-toxic, non-corrosive nitrous oxide (N2O)
- Portable N2O Source (provided) can use "Whippit"-type cartridges (use either 16-gram cartridge for 8 hours of operation, or 8-gram cartridge for 4 hours of operation)
- Very low NO concentration used in comparison to ozone monitors based on NO chemiluminescence
Options :
- Battery
- External particle filter
- Lamp heater for outdoor operation in extreme environments
- Bluetooth wireless data transmission
- 4-20 mA analog current output
- External serial-to-USB adapter
- High-altitude upgrade allows operation up to ~25 km (pressure sensor)