Document ID: chunk:federal_register_of_legislation:F2024L00447:reg:0:p22
Version: federal_register_of_legislation:F2024L00447
Segment Type: reg
Provision Reference: reg 0 (pt 22/57)
Character Range: 152981–155864

of the analyser reading from the reference value, shall not exceed 2 per cent of reading or 0.3 per cent of full scale, whichever is larger.

              4.2.3. Precision

              The precision, defined as 2.5 times the standard deviation of 10 repetitive responses to a given calibration or span gas, shall be no greater than 1 per cent of the full scale concentration for a measurement range equal or above 155 ppm (or ppmC1) and 2 per cent of the full scale concentration for a measurement range of below 155 ppm (or ppmC1).

              4.2.4. Noise

              The noise shall not exceed 2 per cent of full scale. Each of the 10 measurement periods shall be interspersed with an interval of 30 seconds in which the analyser is exposed to an appropriate span gas. Before each sampling period and before each span period, sufficient time shall be given to purge the analyser and the sampling lines.

              4.2.5. Zero response drift

              The drift of the zero response, defined as the mean response to a zero gas during a time interval of at least 30 seconds, shall comply with the specifications given in Table A5/2.

              4.2.6. Span response drift

              The drift of the span response, defined as the mean response to a span gas during a time interval of at least 30 seconds, shall comply with the specifications given in Table A5/2.

       Table A5/2
       Permissible zero and span response drift of analysers for measuring gaseous components under laboratory conditions

Pollutant  Absolute Zero response drift                     Absolute Span response drift

 CO2        ≤ 1000 ppm over 4 h                              ≤ 2 % of reading or ≤ 1000 ppm over 4 h, whichever is larger

 CO         ≤ 50 ppm over 4 h                                ≤ 2 % of reading or ≤ 50 ppm over 4 h, whichever is larger

 PN         5000 particles per cubic centimetre over 4 h     According to manufacturer specifications

 NOX        ≤ 3 ppm over 4 h                                 ≤ 2 % of reading or 3 ppm over 4 h, whichever is larger

 CH4        ≤ 10 ppm C1                                      ≤ 2 % of reading or ≤ 10 ppm C1 over 4 h, whichever is larger

 THC        ≤ 10 ppm C1                                      ≤ 2 % of reading or ≤ 10 ppm C1 over 4 h, whichever is larger

4.2.7. Rise time
              The rise time, defined as the time between the 10 per cent and 90 per cent response of the final reading (t10 to t90; see paragraph 4.4.), shall not exceed 3 seconds.

              4.2.8. Gas drying

              Exhaust gases may be measured wet or dry. A gas-drying device, if used, shall have a minimal effect on the composition of the measured gases. Chemical dryers are not permitted.

              4.3. Additional requirements

              4.3.1. General

              The provisions in paragraphs 4.3.2.