Scott QuadScan II 7400, Руководство по эксплуатации и техническому обслуживанию, Страница: 28 / 121

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This timed delay can prevent nuisance alarms that may occur due to such things as lightening storms, etc. The off
time delay can be programmed for up to 10 seconds, and once activated the timer is decremented once a second
until the time expires.
If the channel is not inhibited (channel status LED flashing),
the associated relay(s) will be affected (non-energized
relays will be energized, and energized relays will be de-
energized). Timer activation can be set to 0 at which time
relay activation will be immediate as described under Set
Point.
Reset Point - A programmed numerical value, which is
compared to the actual gas concentration. When the
concentration is equal to this numerical value, the
associated relay de-activates (changes state) immediately
(See Reset Delay). This is sometimes referred to as
hysteresis.
Reset Delay (On Time) - A delayed relay de-activation can
be programmed for a specific time delay to provide
additional on time for exhaust fans or other corrective
devices.
The on time delay can be programmed for up to 7200
seconds (2 hours) and once activated the timer is
decremented once a second until the time expires.
When the reset timer has expired, the alarm(s) are
deactivated and the channel warn and alarm LEDs are
turned off, unless the alarm(s) are programmed for latching.
Latching alarms require depressing the alarm reset in order
to deactivate the alarm. Pressing the alarm reset button
while the reset timer is in the process of counting down will
automatically expire the timer. The alarm will be
deactivated. Timer activation can be set to zero (0)
disabling this feature.
Figure 10 - Alarm Set For Increasing or Decreasing Gas Concentrations