Page 6 of 16
Process media Temperatures:
Permissible max. medium temperature in the
measuring system
90°C
The process media temperature depends on the ignition temperature of the surrounding gas, vapors or dust, on the
design of the device, especially the pressure change rate and the surface, as well as the ambient temperature and
other external heat sources. The device itself does not have its own heat source.
Rapid pressure changes or pressure surges must always be avoided to protect the movement and
the switching contact. Suitable protective measures, such as a throttle screw, must be used.
The devices are calibrated up to a measuring range of 70 bar with the medium gas, above that liquids are used.
The maximum surface temperature
including the ambient temperature, for
the application on site, depends on the
device type with its technical
specifications. The lowest temperature
limits apply in each case.
Temperatures in explosive atmospheres - Dusts
For the determination of the ignition temperature, the method according to ISO/IEC 80079-20-2 is to be used. This can
only be carried out by the user on site for the individual case. The device-specific properties as well as the limit
temperatures of the dusts and their form as a deposited layer or in the form of a surrounding dust cloud must be taken
into account here. For this reason, the ignition temperatures must be determined separately. In the case of dust layers,
the thickness of the dust layer must be taken into account as a further criterion.
The devices must not be operated in potentially explosive areas of a plant in which an explosive
mixture of gases and dusts is present in the atmosphere.
EPL
Temperature classes
Ignition temperatures
for gases and vapors
Permissible, max. surfaces
incl. ambient temperature
Dry finish Liquid
filled devices
Gb T4 (> 135°C ... ≤ 200°C) 95°C 95°C
T5 (> 100°C ... ≤ 135°C) 95°C 95°C
T6 (> 85°C ... ≤ 100°C) 80°C 80°C
EPL Permissible max. surface temperature of device
Db T95°C (without dust cover and safety factor)
To Next Page
Loading...
