Micropilot FMR62 Commissioning (installation and configuration)
Endress+Hauser 11
λ
S
(Safe)
• Safe failure
• Implication for the safety-related output signal:
The current measured value is output (2) or adopts the safe state (3) and measuring
uncertainty is within the specified safety measured errors
λ
DD
(dangerous detected)
• Dangerous but detectable failure
• Implication for the safety-related output signal:
Results in a failure mode at the output signal (3) and the measuring uncertainty can
exceed the specified safety measured error.
λ
DU
(dangerous undetected)
• Dangerous and undetectable failure
• Implication for the safety-related output signal:
The current measured value is output (4) and the measuring uncertainty can exceed the
specified safety measured error.
3.4.2 Restrictions for safety-related use
• Information on the safety-related signal
• The following restriction also applies for safety-related use:
• Strong, pulse-like EMC interference on the line can result in transient (< 1 s)
deviations ≥ ±2 % in the output signal. Therefore, filtering with a time constant ≥ 1 s
should be performed in the downstream logic unit.
• The error range is device-specific and is defined according to FMEDA (Failure Modes,
Effects and Diagnostic Analysis) on delivery from the factory. It includes all influential
factors described in the Technical Information (e.g. non-linearity, non-repeatability,
hysteresis, zero drift, temperature drift, EMC influences).
The safety-related failures are classified into different categories according to IEC/EN
61508. The table shows the implications for the safety-related analog output signal
and for measuring uncertainty.
3.5 Dangerous undetected failures in this scenario
An incorrect output signal that deviates from the real measured value by more than 2 %,
but is still in the 4 to 20 mA range, is considered a dangerous, undetected failure.
3.6 Useful lifetime of electric components
The established failure rates of electrical components apply within the useful lifetime as
per IEC 61508-2:2010 section 7.4.9.5 note 3.
According to DIN EN 61508-2:2011 section 7.4.9.5 (national footnote N3) appropriate
measures taken by the operator can extend the useful lifetime.
4 Commissioning (installation and
configuration)
4.1 Requirements for personnel
The personnel for installation, commissioning, diagnostics and maintenance must fulfill
the following requirements:
‣
Trained, qualified specialists must have a relevant qualification for this specific function
and task.
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