Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p33
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 33/56)
Character Range: 387691–390307

introduction of a concentration step change at the beginning of the sampling line by switching from zero to span gas. If for a correctly calibrated analyzer after an adequate period of time the reading is ≤  99 per cent compared to the introduced concentration, this points to a leakage problem that shall be corrected.
9.3.5. Response time check of the analytical system
 The system settings for the response time evaluation shall be exactly the same as during measurement of the test run (i.e. pressure, flow rates, filter settings on the analyzers and all other response time influences). The response time determination shall be done with gas switching directly at the inlet of the sample probe. The gas switching shall be done in less than 0.1 second. The gases used for the test shall cause a concentration change of at least 60 per cent full scale (FS).
The concentration trace of each single gas component shall be recorded. The response time is defined to be the difference in time between the gas switching and the appropriate change of the recorded concentration. The system response time (t90) consists of the delay time to the measuring detector and the rise time of the detector. The delay time is defined as the time from the change (t0) until the response is 10 per cent of the final reading (t10). The rise time is defined as the time between 10 per cent and 90 per cent response of the final reading (t90 – t10).
 For time alignment of the analyzer and exhaust flow signals, the transformation time is defined as the time from the change (t0) until the response is 50 per cent of the final reading (t50).
 The system response time shall be  10 s with a rise time of   2.5 seconds in accordance with paragraph 9.3.1.7. for all limited components (CO, NOx, HC or NMHC) and all ranges used. When using a NMC for the measurement of NMHC, the system response time may exceed 10 seconds.
9.3.6. Efficiency test of NOx converter
 The efficiency of the converter used for the conversion of NO2 into NO is tested as given in paragraphs 9.3.6.1. to 9.3.6.8. (see Figure 8).
              Figure 8
              Scheme of NO2 converter efficiency device

9.3.6.1. Test setup
 Using the test setup as schematically shown in Figure 8 and the procedure below, the efficiency of the converter shall be tested by means of an ozonator.
9.3.6.2. Calibration
 The CLD and the HCLD shall be calibrated in the most common operating range following the manufacturer's specifications using zero and span gas (the NO content of which shall amount to about 80 per cent of the operating range and the NO2 concentration of