Air Quality Monitoring Systems
Continuous monitoring of ambient Nitrogen Dioxide
AS32M Analyzer
The European Directive 2008/50/EC requires the measurement of nitrogen dioxide
(NO2) in all urban areas of more than 100 000 inhabitants. Currently, sites located in the
vicinity of roads, directly impacted by vehicle emissions are most likely to experience
poor air quality.
Large touch-screen with animated real-time synoptic
flow diagram optionally
Designed to alleviate potential disadvantages* of the chemiluminiscence method and
to provide the most accurate value for NO2 concentration measurements, the AS32M
analyzer provide fast and accurate measurements.
EXCLUSIVE FEATURES:
Accurate, precise and direct continuous monitoring of ambient NO2
Innovative technology plus touchscreen convenience (optionally)
Visible (450 nm) absorption measurement using patented Cavity
Attenuated Phase Shift (CAPS) technology
Direct measurement of the sample - no chemical conversion required
Measurement of ambient concentrations to 1000 ppbv
Essentially interference-free
Insensitive to presence of varying levels of nitric oxide, aerosols, humidity
and other trace atmospheric species
No Toxic Gas Emissions
Real-time synoptic flow diagram display
Extremely compact, easy to use with minimal maintenance (periodic change of
particle filter)
Linear Response (0-1000 ppbv)
Built-in USB port and serial interface (RS 232 / RS 422)
Full remote emulation of the analyzer
US EPA equivalent method applied
NEW: on board web server compatible with any
internet browser. Es@cloud™ user interface with on-line
help for the display, configuration, maintenance, diagnostics or software updating of the analyser, remotely,
from any PC, tablet or iPhone.
APPLICATIONS :
es@cloud™
TCP/IP remote control with dynamic, multilingual
interface, featuring intuitive navigation by pictograms.
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Ambient air monitoring
Indoor air quality continuous monitoring
Mobile and fixe monitoring laboratories
Traffic stations
NO2 measurement according to the European Directive 2008/50/CE
www.environnement-sa.com
Direct NO2 measurement
Ambient Direct Nitrogen Dioxides Analyzer AS32M
PRINCIPLE OF OPERATION :
Repetability standard deviation at zero: 0.05 ppb
Repetability standard deviation at a level of the
hourly limit value (200µg/m3 ): 0.2 ppb
Short zero drift: 0.75 ppb (24h)
Short span drift: 1.5 ppb
Response time (rise): 16 s
Response time (fall): 16 s
Difference betwen rise time and fall time: <1s
Lack of fit (linearity)(residual from the linear
regression function): <4%
Lack of fit (linearity) at zero (residual at zero):
0.6 ppb (24h)
Sensitivity coefficient of surrounding temperature (0 to 30°C): <0.2 ppb/K
Authonomy: up to one year of NO2 measurements
(on 1/4 h sampling rate)
Valves block for selection of external zero and
span gas
Sample dryer
Ethernet network connection
Integrated web-server with full remote emulation
of the analyser
The Cavity Attenuated Phase Shift nitrogen dioxide (AS32M) monitor as deployed here
operates as an optical absorption spectrometer, utilizing a blue light-emitting diode (LED)
as a light source, a sample cell incorporating two high reflectivity mirrors centered at 450
nm and a vacuum phototube detector. Its efficacy is based on the fact that nitrogen dioxide
(NO2) is a broadband absorber of light in the visible region of the spectrum.
The configuration of the monitor is quite simple and is shown below in the schematic form.
The air sample enters the monitor and passes through a disposable filter cartridge which
removes all particulates in order to prevent contamination of the mirror. The sample then
proceeds through PFA tubing into a stainless steel sample cell at one end and out the other
through tubing where it is directed to a 1 l/min diaphragm pump.
The high reflectivity mirrors are directly attached to the ends of the sample cell, forming the
optical cavity which provides for the concentration measurement, The LED, filter and
appropriate focusing optics are attached directly to the sample cell. The light emanating
from the cell is directed into a vacuum phototube where the resultant signal is integrated,
digitized and sent to the internal computer where all subsequent data processing takes
place. The sample cell contains both pressure and temperature sensors which allow for both
accurate correction of the nitrogen dioxide absorption coefficient and baseline subtraction.
The pressure reading is also used to check on the proper operation of the particle filter.
Sample
Echantillon
450
Drier
Phototube
Filtre optique
Bandpass
filter Vacuum
(détecteur)
Phototube
Pompe
Pump
10 nm
OPTIONS:
Large touch screen permitting one-touch
control of the system as well as pre-configuration of analysis tasks
ESTEL electronic board (1 or 2) with:
› 4 independent analog inputs
› 4 independent analog outputs
› 4 remote control inputs
› 6 dry contacts outputs
SOREL electronic board with:
› 4 dry contacts outputs
› 4 dry contacts inputs
Built-in permeation bench with NO2 tube
Digital Electronics
Mélange
Mixer
fréquence
+ PreAmp
Préampli
*The chemiluminescence - reference method for the measurement of nitrogen dioxide (NO2) and oxides of nitrogen (NOx) is based on the
reaction of nitric oxide (NO) with Ozone (O3) and requires high maintenance and has some negative aspects. Potential errors can arise when
measuring the concentrations of NO and NO2 depending on the duration of the measurement cycle. If part of the light energy produced
by chemiluminescence is lost in collisions with other molecules present in the sample, such as moisture, under-estimation of the sample
may occur. Conversely, a risk of overestimating of NO2 concentrations if other species are converted to NO2 in the NO catalytic oven can
occur. Finally there is a degree of error in the conversion efficiency of the furnace.
Standard version: analyzer equipped with LCD screen
111 BD Robespierre
78304 POISSY - France
Tel. : +33(0)1 39 22 38 00
Web: www.environnement-sa.com
E-mail: info@environnement-sa.com
Distributed by:
Preliminary version for imediate release. Typical spécifications subject to changes without prior notice.
Measurement Range: 0-1 ppm
Detection limit (2s): 0.1 ppb
AS32M-EN_PSO - InDes -06/12
SPECIFICATIONS: