Special Hazards - WIKA 5 Serie Manual De Instrucciones

2. Safety
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 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
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.

2.4 Special hazards

WARNING!
For hazardous media such as oxygen, acetylene, flammable or
toxic gases or liquids, and refrigeration plants, compressors, etc., in
addition to all standard regulations, the appropriate existing codes or
regulations must also be followed.
For additional important safety instructions see chapter 2.3 "Safety instructions
for pressure gauges per ATEX".
WIKA operating instructions pressure gauge model 5 per ATEX
Maximum permissible medium temperature
(in the measuring system)
dry gauges
+65 °C
+80 °C
+105 °C
+160 °C
+200 °C
+200 °C
Maximum permissible medium temperature
(in the measuring system)
< 2/3 T
cloud
< T − 75 K − (reduction depending on the layer thickness)
layer
liquid-filled gauges
+65 °C
+80 °C
+100 °C
+100 °C
+100 °C
+100 °C
EN
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