2. Safety
■
WARNING!
The built-in reed switch does not have its own ignition
source.
It is a 'simple apparatus' in terms of intrinsic safety as defined
in EN 50020.
When powered by a tested and certified intrinsically safe circuit (associated
apparatus), these switches may be used in potentially explosive atmos-
pheres up to category 2 without having to take any further measures.
Operating temperatures
Ambient: -40 ... +60 °C
Medium:
The permissible medium temperature does not only depend
on the instrument design, but also on the ignition temperature
of the surrounding explosive atmosphere. Both aspects have
to be taken into account.
For permissible maximum medium temperatures see table 1.
Attention! With gaseous substances, the temperature may increase as
a result of compression warming. In these cases it may be necessary to
throttle the rate of change
of pressure or reduce the permissible medium temperature.
Table 1: Permissible medium temperature
Temperature class of the
ambient explosive atmosphere
(ignition temperature)
T 6 ( > 85 °C)
T 5 ( > 100 °C)
all other temperature classes
WIKA operating instructions model 232.3x.063 with 851 per ATEX
Pressure gauges must be earthed via the process
connection!
Maximum permissible medium
temperature (in the measuring
system)
+70 °C
+85 °C
+100 °C
GB
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