Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:13:p4
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 13 (pt 4/56)
Character Range: 306761–309631

and set equal to zero. The positive portion shall be included in the integrated value.

7.5. Pre-test procedures

7.5.1. Installation of the measurement equipment

 The instrumentation and sample probes shall be installed as required. The tailpipe shall be connected to the full flow dilution system, if used.

7.5.2. Preparation of measurement equipment for sampling

 The following steps shall be taken before emission sampling begins:
(a) Leak checks shall be performed within 8 hours prior to emission sampling according to paragraph 9.3.4.;
(b) For batch sampling, clean storage media shall be connected, such as evacuated bags;
(c) All measurement instruments shall be started according to the instrument manufacturer's instructions and good engineering judgment;
(d) Dilution systems, sample pumps, cooling fans, and the data-collection system shall be started;
(e) The sample flow rates shall be adjusted to desired levels, using bypass flow, if desired;
(f) Heat exchangers in the sampling system shall be pre-heated or pre-cooled to within their operating temperature ranges for a test;
(g) Heated or cooled components such as sample lines, filters, coolers, and pumps shall be allowed to stabilize at their operating temperatures;
(h) Exhaust dilution system flow shall be switched on at least 10 minutes before a test sequence;
(i) Any electronic integrating devices shall be zeroed or re-zeroed, before the start of any test interval.

7.5.3. Checking the gas analyzers

 Gas analyzer ranges shall be selected. Emission analyzers with automatic or manual range switching are permitted. During the test cycle, the range of the emission analyzers shall not be switched. At the same time the gains of an analyzer's analogue operational amplifier(s) may not be switched during the test cycle.

 Zero and span response shall be determined for all analyzers using internationally-traceable gases that meet the specifications of paragraph 9.3.3. FID analyzers shall be spanned on a carbon number basis of one (C1).

7.5.4. Preparation of the particulate sampling filter

 At least one hour before the test, the filter shall be placed in a petri dish, which is protected against dust contamination and allows air exchange, and placed in a weighing chamber for stabilization. At the end of the stabilization period, the filter shall be weighed and the tare weight shall be recorded. The filter shall then be stored in a closed petri dish or sealed filter holder until needed for testing. The filter shall be used within eight hours of its removal from the weighing chamber.

7.5.5. Adjustment of the dilution system

 The total diluted exhaust gas flow of a full flow dilution system or the diluted exhaust gas flow through a partial flow dilution system shall be set to eliminate water condensation in the system, and to obtain a filter face temperature between 315