GE OptiSonde User Manual page 25

Set Point Alarm
Inner Band Alarm
Installation
For the Set Point alarm type, the alarm band provides hysteresis to
prevent frequent operation of the alarm relay when the parameter is
near the specified value. The relay is activated when the parameter
exceeds the upper limit, and deactivated when the parameter goes
below the lower limit.
Figure 2-9: Set Point Alarm
For the Inner Band alarm type, the alarm relay activates whenever
the parameter value is between the lower and upper limits.
Figure 2-10: Inner Band Alarm
October 2007
2-9