WIKA TR25 Mode D'emploi page 14

3. Safety
When there is a built-in transmitter and/or a digital display, the special conditions from the
type examination certificate (see item 17) apply.
For applications requiring instruments of equipment group II (potentially explosive dust
EN
atmospheres), the following surface temperatures and ambient temperature ranges apply:
Table 2
Marking
II 1D Ex ia IIIC T65 °C Da
II 1/2D Ex ib IIIC T65 °C Da/Db
II 1D Ex ia IIIC T95 °C Da
II 1/2D Ex ib IIIC T95 °C Da/Db
II 1D Ex ia IIIC T125 °C Da
II 1/2D Ex ib IIIC T125 °C Da/Db
1) The values in brackets apply to special designs. These probes are manufactured using special sealing
compounds. Moreover, they feature cases made of stainless steel and cable glands for low-temperature ranges.
When there is a built-in transmitter and/or a digital display, the special conditions from the
type examination certificate (see item 17) apply.
Use in methane atmospheres
Owing to the higher minimum ignition energy of methane, the instruments can also be
used where methane causes a potentially explosive gas atmosphere. The instrument can
optionally be marked with IIC + CH
For applications that require EPL Gb or Db, the instruments marked with "ia" can also be
used in type "ib" measuring circuits.
14
Power Ambient
P temperature
i
range (T )
a
750 mW (-50) -40 ... +40 °C T
1)
650 mW (-50) -40 ... +70 °C
1)
550 mW (-50) -40 ... +80 °C
1)
.
4
WIKA operating instructions model TR25 (Ex i)
Max. surface temperature
(T ) at the probe or
max
thermowell tip
(medium temperature) +
M
self-heating
For this, the special conditions
(17) must be observed.