Traduction de «Système de dilution avec double venturi » (Français → Anglais) :

Calculation of the Mass Flow The particulate mass MPT (g/test) shall be calculated as follows: PT where: Mf = particulate mass sampled over the cycle (mg) MTOTW = total mass of diluted exhaust gas over the cycle as determined in section 2.2.1 (kg) MSAM = mass of diluted exhaust gas taken from the dilution tunnel for collecting particulates (kg) and, Mf = Mf,p + Mf,b , if weighed separately (mg) Mf,p = particulate mass collected on the primary filter (mg) Mf,b = particulate mass collected on the back-up filter (mg) If a double ...[+++] dilution system is used, the mass of the secondary dilution air shall be subtracted from the total mass of the double diluted exhaust gas sampled through the particulate filters.

The secondary dilution system must provide sufficient secondary dilution air to maintain the doubly-diluted exhaust stream at a temperature of less than or equal to 325 K (52°C) immediately before the primary particulate filter.

Partial flow dilution system with twin venturi or twin orifice, concentration measurement and fractional sampling

The double dilution system includes all important parts of the particulate sampling system, like filter holders and sampling pump, and additionally some dilution features, like a dilution air supply and a secondary dilution tunnel.

Although partly a dilution system, the double dilution system is described as a modification of a particulate sampling system in section 2.4, Figure 22, since it shares most of the parts with a typical particulate sampling system.

Figure 9 Partial flow dilution system twin venturi or twin orifice, concentration measurement and fractional sampling