Fulfils European Norm ISO 7996:1985, is certified by US/EPA and is aligned with Norm EN 14211:2005. "Standard method for the measurement of the concentration of Nitrogen Monoxide and Nitrogen Dioxide by Chemiluminescence"

NO2 to NO Converter with increased resistance to Ammonia effects.
Measurements: (NO), (NOx), (NO-NO2-NOx)
Automatic Temperature and Pressure Correction.
Concentrations in ppb, mg/m3, ppm.
Autorange or operator adjustable.
Modular Electronics common with SIR
Models:
    -S-5001 SO2.

    -S-5014 O3.
    -S-506 CO.

    -S-5000 Multi-Gas Calibrator.
Automatic zero correction.
External Sensors can be logged, data can be: stored and pre sented in graphical and tabulated formats.
Electronic Diagnostic Transducers.
Internal Datalogger and Memory.
Graphical Screen with simultaneous presentation of Concentrations and
Diagnostics.
Bi-directional Communication for External Control, “RS232/RS485”.
Calibration: manual, automatic and remote.
Dedicated Menus and Graphical Screen allowing total external control:
     ·Configuration

     ·Diagnostics
     ·Calibrations

     ·Data History
     ·Graphics

     ·Alarm History
     ·Zero/Span

     ·Test of elements
Powerful Calibration and Maintenance Menus (protected by password).
Calibration not only for the pollutans but also for internal electronics of functional parameters.
Multi-tasking software allows viewing test variables while operating.
Adaptive filtering selectable.
Continuous self checking with warning alarms and table of alarms history.
Signals Generation for checking Data.
Acquisition Channels.
Options:

     · PCMCIA Board.
     · Internal Span.
     · NH3 Measurements.

The SIR Model S-5012 Nitrogen Oxides Analyzer is designed to measure the amount of nitric oxide (NO), nitrogen dioxide (NO2) and total oxides of nitrogen (NOx) in a continuous, ambient air sample. The instrument reacts quickly to changes in NO, NO2 and NOx concentrations in the sample, while providing a highly stabilized measurement capability for extended periods,
without repeated adjustments.

The analyzer utilizes the photometric detection of chemiluminescence which results from the gas phase reaction of ozone with NO. In this reaction, some of the resultant NO2 is produced in an electronically excited state; the excited NO2 immediately decays to the ground state (or normal NO2) while emitting light in the spectral region from about 600 nm to 2400 nm, with a peak at
about 1200 nm. This phenomenon is known as chemiluminescence. The intensity of light generated in the reaction is proportional to the concentration of NO present, and the reaction is applicable to the direct measurement of atmospheric concentrations of NO.

Measurements of NO2 are made indirectly by first reducing the NO2 to NO, then reacting the resultant NO with ozone and measuring the light intensity
from the reaction. In practice, the NO2 in a sample of air is first reduced to NO by means of a converter. Any NO, which is already present in the air sample, passes through the converter unchanged, causing a resultant total NOx
concentration equal to NO + NO2. A portion of the air sample is also reacted with ozone without having passed through the converter, which yields the NO concentration. This latter NO measurement is subtracted from the previous NOx measurement (NO + NO2) to yield the final NO2 measurement.

The analyser provides automatic cycling between the NO and NOx measurements, with the concentrations (NO2) updated and displayed after
each cycle. Normal cycle time is approximately 24 seconds.