WIKA R74.100 Mode D'emploi page 9

3. Special conditions for use (X conditions)
2) Maximum surface temperature
For instruments with liquid filling, make sure that the surface
temperature of the application is lower than 100 °C, so that released
liquid filling cannot result in an effective ignition source. This can only
be realized by using an appropriate insulation of hot equipment and
parts which contain hot media.
The surface temperature mainly depends on the medium and
ambient temperature. The instrument itself does not contain any
heating sources. For prevention, consider the maximum medium
temperature as maximum surface temperature , if it is not possible to
determine the real surface temperature even in the case of expected
malfunctions. Instruments with capillary (models F73.100 and
F73.160) are excluded from this restriction.
Instruments for use in hazardous gas/air, vapour/air and mist/air
atmospheres:
Temperature class
(gas application)
T6
T5
T4
T3
T2
T1
1) only for instruments without liquid filling
WIKA additional information models 73, 74 (ATEX)
Maximum permissible surface
temperature (for the end application)
+80 °C
+95 °C
+100 °C (+130 °C)
+100 °C (+195 °C)
+100 °C (+290 °C)
+100 °C (+440 °C)
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EN
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