SCHEDULE 5(ANNEX V to Directive 97/68/EC)ANALYTICAL AND SAMPLING SYSTEM
Figure 12Partial flow dilution system with flow control and fractional sampling
— FCI flow controller (Figures 4, 5 and 10)
For the isokinetic systems (Figures 4 and 5) a flow controller is necessary to maintain a differential pressure of zero between EP and ISP. The adjustment can be done by:
(a)
controlling the speed or flow of the suction blower (SB) and keeping the speed of the pressure blower (PB) constant during each mode (Figure 4);
or
(b)
adjusting the suction blower (SB) to a constant mass flow of the diluted exhaust and controlling the flow of the pressure blower PB, and therefore the exhaust sample flow in a region at the end of the transfer tube (TT) (Figure 5).