SCHEDULE 5(ANNEX V to Directive 97/68/EC)ANALYTICAL AND SAMPLING SYSTEM
Figure 12Partial flow dilution system with flow control and fractional sampling
— FD1, FD2 flow divider (Figure 9)
A set of venturis or orifices is installed in the exhaust pipe EP and in the transfer tube TT, respectively, to provide a proportional sample of the raw exhaust gas. A control system consisting of two pressure control valves PCV1 and PCV2 is necessary for proportional splitting by controlling the pressures in EP and DT.