SICK EuroFID, Operating Instructions Manual

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“Maintenance” Sub-menu Functions
EuroFID · Operating Instructions · 8011094 V2.3 · © SICK AG 125

If the EuroFID is used as a gas detector: Select the threshold values so that the alarm
is reliably triggered before a hazardous condition occurs.
Trigger delay
If you set a delay, the alarm signal is not triggered until after the delay time (setting range:
0.0 … 9.9 seconds). If the measured value is once more inside the threshold value before
the delay has elapsed, no alarm is triggered.
The delay acts in the same manner when the alarm signal is deactivated.

Set the delay as required.

Consider the consequences of an alarm delay.
Hysteresis (differential gap)
When a hysteresis value is set, all alarm signals are only then deactivated when the
measured value is inside the threshold value by the sum of the hysteresis value. In this way
it is possible to prevent an alarm being constantly switched on and off if the measured
value fluctuates around the threshold value. The set hysteresis applies for all threshold
values.

Set the hysteresis as required.
Self-latching function for H2/L2
The alarm signal of the threshold values H2 and L2 can be self-latching. In the “self-
holding” setting the alarm signal is activated after triggering – irrespective of the further
development of the measured value – until it is “reset” with the menu function (
→ P. 130,
§11.13 ).
When the EuroFID is used as a gas detector:

Ensure that the main alarm is self-latching and cannot be reset as long as the alarm is
signaled.

Ensure that failure of the EuroFID has the same effect as an alarm.
Table 13 Threshold value modes and threshold value abbreviation
Mode:
G R Z 2 H 2 L / M e d i a n v a l u e
Mode:
G R Z 3 H
Alarm – when the
threshold value is not
reached
L2 First pre-alarm H0
Pre-alarm – when the
threshold value is not
reached
L1 Second pre-alarm H1
Pre-alarm – when the
threshold value is
exceeded
H1 Alarm H2
Alarm – when the
threshold value is
exceeded
H2 Relations: H0 < H1 < H2
Relations: L2 < L1 < H1 < H2
Example: Threshold value = 40 ppm, hysteresis = 10 %.
➝ The alarm signal is activated at 40 ppm.
➝
The alarm signal is deactivated at 36 ppm.