Каталог Weidmuller: Electronics - Analogue Signal Conditioning

Glossary
Technical appendix/Glossary
Explosion protection types
The ignition protection type is a term used in explosion protection that refers to the
various types of protective construction designed into the product. Ignition protection
types are formulated to minimise the risk that an ignition source will be present in an
explosive atmosphere.
The following ignition protection types are specified:
• For electrical equipment in a gas
• Intrinsic safety Ex i
• Pressure-resistant Ex d encapsulation
• Increased safety Ex e
• Pressurization encapsulation Ex p
• Oil immersion Ex o
• Moulded encapsulation Ex m
• Sand encapsulation Ex q
• Ignition protection type for zone 2 Ex n
• Special ignition protection type Ex s
Explosive atmospheres
• For electrical equipment in dust
• Pressurization encapsulation Ex pD
• Intrinsic safety Ex iD
• Moulded encapsulation Ex mD
• Protection provided by housing Es tD
This is defined as a mixture of flammable materials and oxygen. An ignition leads
to a explosive burning process throughout the entire mixture. Usually the oxygen is
supplied by the surrounding air. Flammable materials may be gases, liquids, vapours,
mists or dusts. Explosion protection considers this to be normal atmospheric
conditions. The explosiveness of the mixture depends of the flammability of the
materials and the concentration of air or oxygen.
F
FDT
Flammability rating
Frequency converter
FDT technology specifies and standardises the integration of communicating devices
from different manufacturers. It makes use of a superimposed device management
program. The key feature is its independence from the communication protocol and
software used by the device and the host system. FDT allows access to any device
from any host using any protocol.
Flammability class specification according to the American UL94 specification.
Duration of burning, annealing time and the burning drop formation are all taken into
account. The highest category is V-0.
Converts frequencies into analogue signals (or vice versa). In-line control systems
can then directly process pulse strings from speed or rotational measurements.
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