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Industrial Automation
Explosion protection
Instruments that operate in explosive environments
(e.g. petrochemical, pharmaceutical, coal mines,...) are subject to particular restrictions.
e.g.
They may not contain anything that can produce sparks or high heat,
such as electrolytic capacitors or batteries without current limitation.
Their design or programming may not be altered after their acceptance.
Their price is higher than that of standard devices because they have to undergo
strict testing (Typentest, type test) by a qualified authority (TÜV in Germany)
Such devices are called Eex - or "intrinsic safety devices" (Eigensichere Geräte, "Ex-Schutz",
protection anti-déflagrante, "Ex" ) and are identified by the following logo:
48/52 2.1 Instrumentation