WIKA TR21-A, Operating Instructions Manual

Page: 5 / 76

EN
14170746.05 03/2022 EN/DE/FR/ES
WIKA additional information model TR21 (Ex i) 5
For applications without transmitters (models TR21-x-xPx and TR21-x-xRx) that require
group II instruments (potentially explosive gas atmospheres), the following temperature
class classification and ambient temperature ranges apply:
Table 1
Marking Temperature
class
Ambient
temperature
range (T
a
)
Max. surface temperature
(T
max
) at the sensor or
thermowell tip
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
T1 ... T5 -50 ... +85 °C T
M
(medium temperature) +
self-heating
For this, the special conditions
must be observed (see chapter
4 “Special conditions for safe
use (X conditions)”).
T6 -50 ... +80 °C
For applications requiring instruments of equipment group II (potentially explosive dust
atmospheres), the following surface temperatures and ambient temperature ranges apply:
Table 2
Marking Power P
i
Ambient
temperature
range (T
a
)
Max. surface temperature
(T
max
) at the sensor or
thermowell tip
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
750 mW -50 ... +40 °C T
M
(medium temperature) +
self-heating
For this, the special conditions
must be observed (see chapter
4 “Special conditions for safe
use (X conditions)”).
650 mW -50 ... +70 °C
550 mW -50 ... +85 °C
1. Ex marking