SCHEDULE 5 (ANNEX V to Directive 97/68/EC)ANALYTICAL AND SAMPLING SYSTEM

Figure 12 Partial flow dilution system with flow control and fractional sampling

— DT dilution tunnel (Figures 4 to 12)

The dilution tunnel:

• shall be of a sufficient length to cause complete mixing of the exhaust and dilution air under turbulent flow conditions,

• shall be constructed of stainless steel with:

  • a thickness to diameter ratio of 0.025 or less for dilution tunnels of greater than 75 mm inside diameter,

  • a nominal wall thickness of not less than 1.5 mm for dilution tunnels of equal to or less than 75 mm inside diameter,

• shall be at least 75 mm in diameter for the fractional sampling type,

• is recommended to be at least 25mm in diameter for the total sampling type.