MT3401E.doc rev.0
21/05/13
Pagina 72 di 86
Fig. 4.5.5 e) Alarm levels setting screen
The left arrow going upwards is indicating the “increasing alarms” of the LEL profile
where the alarm levels from alarm 1 to alarm 3 correspond to increasing concentration.
The configuration software is checking the user input for plausibility. There are some
general rules e.g. alarm level not below 5% of the measuring range, no higher alarm
(alarm 2 or 3) is settable to a level lower than the lower alarm (alarm 1 or 2). Other
restrictions are specified in the measurement tasks (profiles).
The horizontal red bars indicate for each alarm threshold the range within which alarms
can be set or modified.
In the profile
“Oxygen deficiency”
the Oxygen concentration corresponding to alarm 1
will be higher than for alarm 2 and alarm 3. This will be indicated by the left arrow going
downwards for “decreasing alarms”.
“Overrange”
typically is fixed at 100% of the measuring range. Only if in a profile a
fourth alarm level is required “Overrange” will be used as this fourth alarm and the value
is settable.
The
“Hysteresis”
value indicates how variations in the signal will be ignored when in
close proximity to the alarm threshold.
Modification of alarm levels
The values can be modified in steps by touching the
–
on the left or the
+
on the right
side of the horizontal alarm bar or by typing the numbers into the numeric indication on
the right side. Due to the modification of one alarm set point also the range of the red
bars for the alarms will be modified accordingly. If the typed value for an alarm level is
outside of the accepted range the plausibility check will modify it automatically, e.g.
