Doric Instruments 5000D Digital Process Indicator and Miniature Datalogger - Manual (Page 20)

19
Hysteresis
Hysteresis or deadband is used to delay the unlatching of a
tripped relay. Hysteresis may be selected within the alarm
menu as either ON or OFF. Hysteresis is selectable from 0-99
degrees in 1
°
increments. For example, a limit with a
hysteresis value of 5 assigned to it means that the display
value must return 5
°
below the alarm setpoint before the
alarm condition is cleared (the relay resets). Hysteresis
assumes negative values for HIGH limits and positive values
for LOW limits.
Delay
Programming the meter for alarm delay prevents an alarm
trip for a specified period of time (0-9 seconds). An alarm
delay would be used whenever an unstable or noisy input
signal is present. By filtering out short duration alarm
conditions, alarm delay prevents unnecessary alarms from
occurring.
TIME
upper
deviation
limit
lower
deviation
limit
operating
temp