Distillation Process Analyzer DPA-4.5
Safety
2.3.2 Ignition protection types and certificates
The device and its components provide explosion protection by
various types of ignition protection. The principles of these are
briefly described in the following section:
Pressurization Ex p
The penetration of an external, potentially explosive atmosphere
into the box of electrical components is prevented by a protective
gas (in this case, air) maintained in the box interior under
overpressure in relation to the surrounding atmosphere. The
maintenance of the pressure is monitored.
Pressure-resistant enclosure Ex d
Parts which could be ignited by a potentially explosive atmosphere
are kept inside a box. The box is designed in such a way that in the
event of an explosion in the interior, the pressure is maintained and
thereby prevents the spread of the explosion to the explosive
atmosphere surrounding the box.
Increased safety Ex e
For electrical components for which ignition sources are not
present during normal operation, impermissibly high temperatures,
sparks and electric arcs are prevented by additional measures.
Cast encapsulation Ex m
Parts which could ignite a potentially explosive atmosphere by
sparks or heat are embedded in a grouting so that this cannot
occur.
Intrinsic safety Ex i
Intrinsically safe electrical circuits cause no sparks or thermal
effects that might ignite a potentially explosive atmosphere of the
subgroups IIA, IIB or IIC.
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