WIKA TR21 Serie Informations Complémentaires page 6

1. Ex marking
For applications with transmitters (TR21-x-xTT, TR21-x-xTB) that require group II
instruments (potentially explosive gas atmospheres), the following temperature class
classification and ambient temperature ranges apply:
EN
Table 3
Hazardous gas atmosphere Temperature
ATEX IECEx
II 1G Ex ia IIC T1 ... T6 Ga
II 1/2G Ex ia IIC T1 ... T6
Ga/Gb
II 2G Ex ia IIC T1 ... T6 Gb
For applications requiring instruments of equipment group II (potentially explosive dust
atmospheres), the following surface temperatures and ambient temperature ranges apply:
Table 4
Hazardous dust atmosphere Power P
ATEX IECEx
II 1D Ex ia IIIC T135 °C Da
II 1/2D Ex ia IIIC T135 °C Da/Db
II 2D Ex ia IIIC T135 °C Db
For applications that require EPL Gb or Db, the instruments designated as "ia" can also be
used in type "ib" measuring circuits, with the same connection parameters.
Thus the entire measuring circuit (including the sensor circuit) is an "ib" circuit. Instruments
that have been operated in a power supply circuit of type "ib" cannot be re-used in a power
supply circuit of type "ia".
6
Ambient
class temperature
range (T
T1 ... T4 -40 ... +85 °C
T5 -40 ... +60 °C
T6 -40 ... +45 °C
Ambient
i
temperature
range (T
750 mW -40 ... +40 °C
650 mW -40 ... +70 °C
550 mW -40 ... +85 °C
WIKA additional information model TR21 (Ex i)
Max. surface temperature
(T ) at the sensor or
max
) thermowell tip
a
T (medium temperature) +
M
self-heating
For this, the special conditions
must be observed (see chapter
4 "Special conditions for safe
use (X conditions)").
Max. surface temperature
(T ) at the sensor or
max
) thermowell tip
a
T (medium temperature) +
M
self-heating
For this, the special conditions
must be observed (see chapter
4 "Special conditions for safe
use (X conditions)").