Thermo Scientific 42i-Y NOy Analyzer

42i-Y measures NOy, the total of reactive nitrogen oxides excluding NH3 and N2O, by the chemiluminescence method. It has a single-chamber, single photomultiplier tube design and works from sub-ppb level up to 1000 ppb. The detection limit is below 50 ppt at a 120-second average. The manufacturer states that the instrument meets US EPA NCore network NOy requirements.

• Standard dual range and auto-range.
• 10-second response time, temperature and pressure correction.
• User-selectable concentration alarm levels.
• Operating temperature 0-45 °C; span drift and linearity ±1 percent of full scale, zero noise below 25 ppt RMS.
• i-Series: Ethernet, one-touch programming, flash memory and easy component access.

Variants available include voltage (100-240 V), internal zero/span assembly, ozone dryer (Drierite or permeation), I/O expansion card and tabletop or rack-ear mounting. The standard converter is molybdenum.

NOy measurement is used at urban and remote stations to study photochemical ozone formation and nitrogen oxide transport. Placing the converter as close as possible to the sample inlet prevents NOy species being lost in the line.

For NOy measurement, Tetra installs the converter close to the sample inlet, prepares a sample line that avoids line losses and commissions with multi-point calibration. Converter and dryer consumables are included in the maintenance service.