WIKA 2 Series - Page 12

EN
WIKA operating instructions pressure gauge, model 2 per ATEX12
14375375.01 12/2019 EN/DE
2. Safety
Potentiallyexplosivegasatmosphere
Requiredtempera-
ture class
(ignition temper-
ature of gas or
vapour)
Maximum permissible surface temperature
oftheinstrument(fortheendapplication)
Models 232, 262,
PG23CP(unlled
instruments)
Models 233, 263,
PG23LT, PG23CP
(lledinstruments)
T6 (T > 85 °C) +65 °C +65 °C
T5 (T > 100 °C) +80 °C +80 °C
T4 (T > 135 °C) +105 °C +100 °C
T3 (T > 200 °C) +160 °C +100 °C
T2 (T > 300 °C) +200 °C +100 °C
T1 (T > 450 °C) +200 °C +100 °C
Hazardous dust atmosphere
For dusts, the procedure specied 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
Maximum permissible surface temperature
oftheinstrument(fortheendapplication)
Dust cloud: T
cloud
< 2/3 T
cloud
Dust layer: T
layer
< T
layer
− 75 K − (reduction depending on the layer thick-
ness)
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.