WIKA TG53 Instructions Complémentaires page 10

3. Special conditions for use (X conditions)
Instruments for use in hazardous gas/air, vapour/air and mist/air
atmospheres:
Temperature class
EN
(gas application)
T6
T5
T4
T3
T2
T1
1) only for instruments without liquid filling
Hazardous dust atmosphere
For dusts, the procedure specified in ISO/IEC 80079-20-2 for
determining 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
Dust layer T
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.
3) Mount the instrument in such a way that, taking into consideration
the influence of convection and heat radiation, no deviation above or
below the permissible ambient and medium temperatures can occur.
10
Maximum permissible surface
temperature (for the end application)
80 °C
95 °C
130 °C
195 °C
250 °C (290 °C)
250 °C (440 °C)
Maximum permissible medium
temperature (in the measuring system)
< 2/3 T
cloud
< T
layer layer
layer thickness)
WIKA additional information models TG53, TG54 (ATEX)
1)
1)
cloud
− 75 K − (reduction depending on the