Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:110:p4
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 110 (pt 4/59)
Character Range: 613108–616058

an adequate period of time the reading is about 1 % low compared to the introduced concentration, these points to calibration or leakage problems.'

         (iii)   The following section 1.5 is inserted:

        '1.5. Response time check of 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 % 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 % of the final reading (t10). The rise time is defined as the time between 10 % and 90 % response of the final read- ing (t90 – t10).

              For time alignment of the analyzer and exhaust flow signals in the case of raw measurement, the transformation time is defined as the time from the change (t0) until the response is 50 % of the final reading (t50).

              The system response time shall be ≤ 10 seconds with a rise time ≤ 3,5 seconds for all limited components (CO, NOx, HC or NMHC) and all ranges used.'

         (iv)   Former section 1.5 is replaced by the following:

        '1.6. Calibration

        1.6.1. Instrument assembly

              The instrument assembly shall be calibrated and calibration curves checked against standard gases. The same gas flow rates shall be used as when sampling exhaust.

        1.6.2. Warming-up time

              The warming-up time should be according to the recommendations of the manufacturer. If not specified, a minimum of two hours is recommended for warming up the analysers.

        1.6.3. NDIR and HFID analyser

              The NDIR analyser shall be tuned, as necessary, and the combustion flame of the HFID analyser shall be optimised (section 1.8.1).

        1.6.4. Establishment of the calibration curve

                -          Each normally used operating range shall be calibrated

                -          Using purified synthetic air (or nitrogen), the CO, CO2, NOx and HC analysers shall be set at zero

                -          The appropriate calibration gases shall be introduced to the analysers, the values recorded, and the calibration curve established

                -          The calibration curve shall be established by at least 6 calibration points (excluding