4 System Overview
9
4.2.
Definitions
Air Supply
primary and secondary dilution air supply part of testo ASET15-1
Evaporation
Tube
thermally insulated stainless steel tube with electronically controlled
heater on the testo ASET15-1 rear side for heating up the primarily
diluted measuring gas.
Raw gas
undiluted aerosol from the emission source
Measuring gas
primary or secondary diluted aerosol from the emission source
(combustion engine or CVS).
Primary dilution
Takes place in testo MD19-3E rotating disk diluter before the
measuring gas enters into the evaporation tube.
Secondary
dilution
Dilution of the primarily diluted and thermally conditioned measuring
gas at the outlet of the evaporation tube.
4.3.
Abbreviation, Units and Symbols
testo ASET15-1
Air Supply Evaporation Tube; 15 = 15
l/min air supply; 1 = version 1
CVS
Constant Volume Sample
– fullstream dilution tunnel in vehicle test
benches
DF
Dilution Factor in secondary dilution: DF = (Q
AS
+ Q
MD
)/ Q
MD
PCRF
Particle Concentration Reduction Factor
LED
Light Emitting Diode
– used as signal lamps at the front of the testo
ASET15-1
l/min (STP)
Standard liter per minute: unit for gas volume flow at Standard
Temperature and Preasure (STP: 1013,25 hPa, 0°C)
testo MD19-3E
Type designation for Testo rotating disk diluters
Q
MD
primary diluted measuring gas flow from the testo MD19-3E primary
diluter
Q
AS
secondary dilution air flow from the air supply part of testo ASET15-1
Q
MG
secondary diluted measuring gas flow to the connected instrumentation
Q
EX
excess secondary diluted measuring gas gas flow
