Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p3
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 3/27)
Character Range: 557005–560357

shall comply with the linearity requirements specified in Table 7 of this annex. The linearity verification in accordance with paragraph 9.2.1. of this annex, shall be performed at least every 12 months or whenever a system repair or change is made that could influence calibration. With the prior approval of the Type Approval Authority, less than 10 reference points are permitted, if an equivalent accuracy can be demonstrated.
              For the linearity verification, a NH3 gas that meets the specifications of paragraph A.7.4.2.7. shall be used. The use of reference cells that contain NH3 span gas shall be permitted.
              Instruments, whose signals are used for compensation algorithms, shall meet the linearity requirements specified in Table 7 of this annex. Linearity verification shall be done as required by internal audit procedures, by the instrument manufacturer or in accordance with ISO 9000 requirements.
              A.7.4.2.              Analyser specifications
              The analyser shall have a measuring range and response time appropriate for the accuracy required to measure the concentration of NH3 under transient and steady state conditions.
              A.7.4.2.1.              Minimum detection limit
              The analyser shall have a minimum detection limit of < 2 ppm under all conditions of testing.
              A.7.4.2.2.              Accuracy
              The accuracy, defined as the deviation of the analyser reading from the reference value, shall not exceed ± 3 per cent of the reading or ± 2 ppm, whichever is larger.
              A.7.4.2.3.              Zero drift
              The drift of the zero response and the related time interval shall be specified by the instrument manufacturer.
              A.7.4.2.4.              Span drift
              The drift of the span response and the related time interval shall be specified by the instrument manufacturer.
              A.7.4.2.5.              System response time
              The system response time shall be  20 s.
              A.7.4.2.6.              Rise time
              The rise time of the analyser shall be  5 s.
              A.7.4.2.7.              NH3 calibration gas
              A gas mixture with the following chemical composition shall be available.
              NH3 and purified nitrogen.
              The true concentration of the calibration gas shall be within ±3 per cent of the nominal value. The concentration of NH3 shall be given on a volume basis (volume per cent or volume ppm).
              The expiration date of the calibration gases stated by the manufacturer shall be recorded.
              A.7.5.              Alternative systems
              Other systems or analysers may be approved by the Type Approval Authority, if it is found that they yield equivalent results in accordance with paragraph 5.1.1. of this annex.
              "Results" shall refer to average cycle specific NH3 concentrations.

                  Annex 4 ‑ Appendix 8 Particle number emissions measurement equipment
A.8.1. Specification
              A.8.1.1. System overview
              A.8.1.1.1. The particle sampling system shall consist of a probe or sampling point extracting a sample from a homogenously mixed flow in a dilution system as described in Appendix 2 to this annex, paragraph