WIKA 21 20 Série Mode D'emploi page 6

3. Technical data and intended use
Operating Temperature
Ambient: -5 ... +60 °C
GB
Attention: Footnote 1) under table 1 must be absolutely taken into account!
Medium: see table 1
Attention! In the case of gaseous substances, the temperature may increase
due to compression warming. In these cases it may be necessary to throttle
the rate of change of pressure or reduce the permissible temperature of the
pressure medium.
Temperature Class of the
ambient atmosphere
(ignition temperature)
T 6 (> 85 °C)
T 5 (> 100 °C)
T 4 (> 135 °C)
T 3 (> 00 °C)
T  (> 300 °C)
T 1 (> 455 °C)
Table 1: Permissible medium temperature (only mechanical part)
1) The permissible uppper ambient temperature for the electrical components is determined by the
electrical connection values and the ignition temperature of the ambient gases, vapours and dusts.
Therefore the maximum permissible ambient temperatures specified in the EC-type examination
certificates for slot-type sensors and SN sensors must be observed as well. The lower of these
two values is to be considered the maximum permissible ambient temperature!
Installation
In order to ensure that with Model 3X pressure can be safely and reliably

vented through the case back, a distance of at least 5 mm must be left free
behind the case!
In order to avoid any additional heating, the instruments must not be

exposed to direct solar irradiation while in operation!
With filled versions the ventilating valve (pressure ranges ≤10 bar) at the top

of the case must be opened prior to commissioning!
6
(with inductive contacts in safety pattern version
Models 831.XX-SN up to -40 °C)
Maximum permissible medium temperature
(in the pressure system)
Model 1.0
+70 °C
+80 °C
+80 °C
+80 °C
+80 °C
+80 °C
WIKA Operating instructions pressure gauges Model  with 831 per ATEX
Models 3 Models 33
(dry gauges) (liquid filled gauges)
+70 °C +70 °C
+85 °C +85 °C
+10 °C +100 °C
+185 °C +100 °C
+00 °C +100 °C
+00 °C +100 °C