WIKA 232.50.100 Betriebsanleitung Seite 12

2. Safety
Potentially explosive gas atmosphere
Required tempera-
ture class
EN
(ignition temper-
ature 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 thick-
ness per IEC/EN 60079-14.
Ignition tempera-
ture 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.
Explosive atmosphere consisting of hybrid mixtures
The instruments must not be used in areas in which an atmosphere
consisting of explosive hybrid mixtures (dusts mixed with gases) can
occur.
12
Maximum permissible surface temperature
of the instrument (for the end application)
Models 232, 262,
PG23CP (unfilled
instruments)
+65 °C
+80 °C
+105 °C
+160 °C
+200 °C
+200 °C
Maximum permissible surface temperature
of the instrument (for the end application)
< 2/3 T
cloud
< T − 75 K − (reduction depending on the layer thick-
layer
ness)
WIKA operating instructions pressure gauge, model 2 per ATEX
Models 233, 263,
PG23LT, PG23CP
(filled instruments)
+65 °C
+80 °C
+100 °C
+100 °C
+100 °C
+100 °C