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  • NOx
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  • Measures 0 to 3 to 0 to 3,000ppm full scale NO/NO2/NOx
  • Heated version available
  • Low flow sampling at 0.6 lpm
  • Versatile solution for emissions monitoring and testing
  • Automatic calibration and full scale auto-ranging
  • Internal converter for NO2 to NO
  • Zero and span with TCP/IP or RS232


The Servomex NOx Gas Analyzer uses the time-proven Chemiluminescence Detector (CLD) method to measure NO or NO/NO2/NOx concentrations all in one analyzer – perfect for continuous monitoring for industrial stationary sources emissions or ambient air, and fast enough for emissions testing in engines and vehicles.

The analyzer uses ozone (O3) which reacts with the nitric oxide (NO) in the sample stream, yielding an excited state of NO2 (NO2*) plus oxygen (O2). As the NO2* returns to a more stable state, it produces a chemiluminescent light of intensity proportional to the concentration of NO that was converted into NO2. A photodiode detector measures the light to determine a ppmv NO value.

To produce a total NOx signal, an internal converter turns any NO2 in the sample into NO. This stream is then subjected to O3 gas – the resultant reaction is directly proportional to the total NOx concentration. The analyzer calculates the final NO2 concentration from the NOx converter efficiency.