Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:110:p3
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 110 (pt 3/59)
Character Range: 610575–613394

325 K (52 °C), and, if necessary propose an alternative tem- perature to be applicable for type-approval of new types from 1 October 2008.'

  (h)     Appendix 5 is amended as follows:

         (i)       The following section 1.2.3 is added:

        '1.2.3. Use of precision blending devices

              The gases used for calibration and span may also be obtained by means of precision blending devices (gas dividers), diluting with purified N2 or with purified synthetic air. The accuracy of the mixing device must be such that the concentration of the blended calibration gases is accurate to within ± 2 %. This accuracy implies that primary gases used for blending must be known to an accu- racy of at least ± 1 %, traceable to national or international gas standards. The verification shall be performed at between 15 and 50 % of full scale for each calibration incorporating a blending device.

              Optionally, the blending device may be checked with an instrument which by nature is linear, e.g. using NO gas with a CLD. The span value of the instrument shall be adjusted with the span gas directly connected to the instrument. The blending device shall be checked at the used settings and the nominal value shall be compared to the measured concentration of the instrument. This dif- ference shall in each point be within ± 1 % of the nominal value.'

         (ii)     Section 1.4 is replaced by the following:

        '1.4. Leakage test

              A system leakage test shall be performed. The probe shall be disconnected from the exhaust system and the end plugged. The analy- ser pump shall be switched on. After an initial stabilisation period all flow meters should read zero. If not, the sampling lines shall be checked and the fault corrected.

              The maximum allowable leakage rate on the vacuum side shall be 0,5 % of the in-use flow rate for the portion of the system being checked. The analyser flows and bypass flows may be used to estimate the in-use flow rates.

              Alternatively, the system may be evacuated to a pressure of at least 20 kPa vacuum (80 kPa absolute). After an initial stabilisation period the pressure increase Δp (kPa/min) in the system should not exceed:

Δp = p / Vs × 0,005 × qvs

              where:

              Vs = system volume, l
              qvs = system flow rate, l/min

              Another method is the introduction of a concentration step change at the beginning of the sampling line by switching from zero to span gas. If after 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