Measurement Units; Soot Concentration [Mg/M ]; Filter Smoke Number [Fsn] - TESTO 338 Instruction Manual

3.5.

Measurement units

3.5.1. Soot concentration [mg/m
With the filter loading, via the volume that causes the blackening, it
is possible to infer the soot concentration (SC = soot concentration)
of the flue gas. This unit is calculated via the measured filter
loading and the effective length. The effective length corresponds
to the flue gas column which is actually drawn through the filter
paper. The filter loading and the effective length are understood in
SC=
FL
the following context:
SC: Soot concentration
FLeff: effective filter loading
Leff: effective length
3.5.2.

Filter smoke number [FSN]

The filter smoke number (FSN) is a standardised unit. It
corresponds to the paper blackening caused by the intake of a flue
gas column with a reference length of 405 mm (under reference
conditions: 1000 mbar, +25 °C) on the filter paper. In the case of
the testo 338, a longer flue gas column is drawn through the filter
paper to increase sensitivity. This is converted to a reference length
after the measurement. During the measurement, the flue gas
volume taken in by the testo 338 is adjusted to the current ambient
conditions (pressure, temperature) so that it corresponds to the
volume under reference conditions. This gives a measuring value
irrespective of local conditions.
eff
L
eff
Filter smoke number/paper blackening
]
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3 Specifications
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