GAS-1060 Nitrogen Dioxide Analyzer
The GAS-1060 Nitrogen Dioxide (NO2) Analyzer with Cavity Attenuated Phase Shift (CAPS) spectroscopy technology from Met One Instruments Powered by Acoem allows direct measurement of NO2, rather than an indirect calculation from a chemiluminescence analyzer.
Using a modulated blue LED light source, the detector measures the phase shift attributable to the level of NO2 in the measurement cell over an average path length of several kilometers.
US EPA-approved.
Operations / Interface
Theory of Operation:
The measurement of nitrogen dioxide (NO2) utilizes Cavity Attenuated Phase Shift (CAPS) spectroscopy technology.
Sample air is filtered to remove particulates and dried before entering the precision stainless steel 264 mm measurement cell.
The measurement cell contains two high reflectivity mirrors located at either end to provide an average optical path length of several kilometers.
A modulated blue light source emits a narrow band wavelength of 450 nm which is used as a photon source for the cavity attenuation process. The LED is pulsed into the optical cavity and the photon “leakage”, as a result of the optical cavity, is determined through the output voltage measured by the vacuum photo diode detector.
The detector is used in conjunction with a narrow band-pass interference filter (450 nm).
During LED modulation, the photon leakage of the cavity, combined with photon absorption from gas molecules within the cavity, produces a shift in the phase of the response signal measured by the detector.
By measuring the shift in phase angle without NO2 in the sample (background), a baseline phase shift can be measured. During operation, NO2 gas molecules within the cavity will increase photon decay, and this will be reflected as a change in phase of the detector signal. This change in phase is proportional to the NO2 concentration.
Using this principle, it is possible to reliably measure NO2 concentrations of well under 1 ppb and up to 1000 ppb. Due to the continuous measurement of the sample, the analyzer has a fast response time of less than 30 seconds.
For Complete Specifications and Product Information, please view the Product Data Sheet.