Document ID: chunk:federal_register_of_legislation:F2024L00447:reg:0:p30
Version: federal_register_of_legislation:F2024L00447
Segment Type: reg
Provision Reference: reg 0 (pt 30/57)
Character Range: 174452–177375

the aerosol. The sensitivity of the analysers to shocks, vibration, aging, variability in temperature and air pressure as well as electromagnetic interferences and other impacts related to vehicle and analyser operation shall be limited as far as possible and shall be clearly stated by the equipment manufacturer in its support material. The PN analyser shall only be used within its manufacturer's declared parameters of operation. An example of a PN analyser setup is provided in Figure A5/1.

       Figure A5/1
       Example of a PN analyser setup: Dotted lines depict optional parts. EFM = Exhaust mass Flow Meter, d = inner diameter, PND = Particle Number Diluter.

              The PN analyser shall be connected to the sampling point via a sampling probe which extracts a sample from the centreline of the tailpipe tube. As specified in paragraph 3.5. of Annex 4, if particles are not diluted at the tailpipe, the sampling line shall be heated to a minimum temperature of 373 K (100 °C) until the point of first dilution of the PN analyser or the particle detector of the analyser. The residence time in the sampling line shall be less than 3 s.

              All parts in contact with the sampled exhaust gas shall be always kept at a temperature that avoids condensation of any compound in the device. This can be achieved for example by heating at a higher temperature and diluting the sample or oxidizing the (semi)volatile species.

              The PN analyser shall include a heated section at wall temperature ≥ 573 K. The unit shall control the heated stages to constant nominal operating temperatures, within a tolerance of ± 10 K, and provide an indication of whether or not heated stages are at their correct operating temperatures. Lower temperatures are acceptable as long as the volatile particle removal efficiency fulfils the specifications of paragraph 6.4.

              Pressure, temperature and other sensors shall monitor the proper operation of the instrument during operation and trigger a warning or message in case of malfunction.

              The delay time of the PN analyser shall be ≤ 5 s.

              The PN analyser (and/or particle detector) shall have a rise time of ≤ 3.5 s.

              Particle concentration measurements shall be reported normalised to 273 K and 101.3 kPa. If necessary, the pressure and/or temperature at the inlet of the detector shall be measured and reported for the purposes of normalizing the particle concentration.

              PN systems that comply with the calibration requirements of UN Regulation Nos 83 or 49 or UN Regulation No. 154 on WLTP automatically comply with the calibration requirements of this annex.

              6.2. Efficiency requirements

              The complete PN analyser system including the sampling line shall fulfil the efficiency requirements of Table A5/3a.

    Table A5/3a
    PN analyser (including