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ATEX Instruction Manual
ETC01035
January 2004
MLT 2 / BINOS
®
100 F
Emerson Process Management Manufacturing GmbH & Co. OHG
1 - 1
SECTION 1
Technical Description
1-1 Application and Principle of Operation
The gas analyzers of type BINOS
®
100 F
and MLT 2 are intended to measure gas
components within gas mixtures. In
combination with an appropriate certified
pressurization system (protection method
„Pressurized Enclosure“ EEx p) they can be
installed and operated in hazardous areas
of Category 2 or Category 3.
Pressurization acts as external explosion
protection and prevents external explosive
atmosphere to penetrate into the analyzer
by holding the enclosure at an overpressure
compared to the surrounding
The type of purge system used varies
dependent on the area where the analyzer
is intended to be installed. Both systems
offer two modes of operation:
• EEx p with continuous flow
and
• EEx p with leakage compensation.
Dependent on the sample gas composition
it may be necessary to take care of internal
explosion protection which refers to the
sample gas path (containment system) in
the analyzer.
One of the following protection methods is
used:
• Nonflammable gases and gas
mixtures below the LEL: It must be
ensured that the sample gas in the
containment system always remains
below the lower explosive limit!
• Flammable gases and gas mixtures
may be analyzed using an analyzer with
pressurization method „leakage
compensation“ when the sample gas is
diluted below ¼ LEL outside the
analyzer, so the resulting sample gas
is to be categorized „nonflammable“.
The diluting system must ensure that the
gas in the containment system always
remains below ¼ LEL.
• Flammable gases and gas mixtures
may be analyzed using an analyzer with
pressurization method „leakage
compensation“ or „continuous flow“
when the analyzer enclosure has an
internal overpressure of > 50 Pa over
the pressure in the containment system.
To ensure this condition a differential
pressure switch is used and connected
between containment system and
analyzer enclosure. In case the
pressure decreases below the level of
50 Pa the switch is activated and forces
the purging unit to disconnect the
analyzer from it’s power supply. If more
than one switch is needed because
more than one flammable gas is
supplied to the analyzer, the contacts of
these switches have to be connected
in series. Purge medium may be inert
gas or air. Flame arrestors are required
for all gas inlets and outlets carrying
flammable gases.
• Explosive gases must not be
connected to the analyzer!