WIKA 232.50.100 Betriebsanleitung Seite 8

2. Safety
Permissible medium temperature
The permissible medium temperature not only depends on the instru-
ment design, but also on the ignition temperature of the surrounding
EN
gases, vapours or dusts. Both aspects have to be taken into account.
Potentially explosive gas atmosphere
Required
temperature class
(ignition
temperature of gas
or vapour)
T6 (T > 85 °C)
T5 (T > 100 °C)
T4 (T > 135 °C)
T3 (T > 200 °C)
T2 (T > 300 °C)
T1 (T > 450 °C)
Hazardous dust atmosphere
For dusts, the procedure specified in ISO/IEC 80079-20-2 for determin-
ing the ignition temperature has to be applied. The ignition temperature
is determined separately for dust clouds and dust layers, respectively.
For dust layers, the ignition temperature depends on the dust layer
thickness per IEC/EN 60079-14.
Ignition temperature
of dust
Dust cloud: T
Cloud
Dust layer: T
Layer
The permissible maximum medium temperature must not exceed the
lowest determined value, even in case of a malfunction.
8
Maximum permissible medium temperature
(in the measuring system)
Models 232, PG23CP
(dry gauges)
+70 °C
+85 °C
+120 °C
+185 °C
+200 °C
+200 °C
Maximum permissible medium temperature
(in the measuring system)
< 2/3 T
< T
Layer
WIKA operating instructions pressure gauge, model 2 per ATEX
Models 233, PG23LT, PG23CP
(liquid-filled gauges)
+70 °C
+85 °C
+100 °C
+100 °C
+100 °C
+100 °C
Cloud
− 75 K − (Reduction depending on the layer
thickness)