Document ID: chunk:federal_register_of_legislation:F2008C00323:reg:120:p11
Version: federal_register_of_legislation:F2008C00323
Segment Type: reg
Provision Reference: reg 120 (pt 11/23)
Character Range: 266042–269178

the vent;

         3.2.3.12. gas-tight, quick-lock coupling elements (Q), between the quick-acting valves and the sampling bags; the couplings shall close automatically on the sampling-bag side. As an alternative, other ways of transporting the samples to the analyser may be used (three-way stop-cocks, for instance);

         3.2.3.13. bags (B) for collecting samples of the diluted exhaust gas and the dilution air during the tests; they shall be of sufficient capacity not to impede the sample flow; the bag material shall be such as to affect neither the measurements themselves nor the chemical composition of the gas samples (for instance: laminated polyethylene/polyamide films, or fluorinated poly-hydrocarbons);

         3.2.3.14. a pressure gauge (G), which shall be precise and accurate to within  0.4 kPa;

         3.2.3.15. a temperature sensor (T), which is precise and accurate to within  1 K and has a response time of 0.1 seconds to 62 per cent of a temperature change (as measured in silicon oil);

         3.2.3.16. a measuring critical-flow venturi tube (MV), to measure the flow volume of the diluted exhaust gas;

         3.2.3.17. a blower (BL), of sufficient capacity to handle the total volume of diluted exhaust gas.

         3.2.3.18. The capacity of the CFV-CVS system shall be such that, under all operating conditions which may possibly occur during a test, there will be no condensation of water. This is generally ensured by using a blower whose capacity is:

         3.2.3.18.1. twice as high as the maximum flow of exhaust gas produced by accelerations of the driving cycle; or

         3.2.3.18.2. sufficient to ensure that the CO2 concentration in the dilute exhaust sample bag is less than 3 per cent by volume.

         3.2.4.  Additional equipment required when testing compression-ignition-engined vehicles

         To comply with the requirements of paragraphs 4.3.1.1. and 4.3.2. of Annex 4, the additional components shown within the dotted lines of Figure 5/4 shall be used when testing compression-ignition-engined vehicles.

                   Fh  is a heated filter,

                   S3  is a hydrocarbon sampling point,

                   Vh  is a heated multi-way valve,

                   Q  is a quick connector to allow the ambient air sample BA to be analysed on the HFID,

                   HFID  is a heated flame ionisation analyser,

                   R and I  are a means of integrating and recording the instantaneous hydrocarbon concentrations,

                   Lh  is a heated sample line.

         All heated components shall be maintained at 463 K (190 C)  10 K.

         If compensation for varying flow is not possible, then a heat exchanger (H) and temperature control system (Tc) as described in paragraph 3.1.3. of this Appendix will be required to ensure constant flow through the venturi (Mv) and thus proportional flow through S3 particulate sampling system.

               S4 Sampling probe in dilution tunnel,

               Fp Filter unit, consisting of two series-mounted filters; switching unit for further parallel-mounted pairs