GRAPHTEC midi LOGGER HV User Manual page 147

Dead zones (hysteresis) of trigger and alarm levels
Trigger and alarm levels are provided with a dead zone (hysteresis) in order to prevent false detection due to
noise.
The following figure shows the dead zone (hysteresis).
< Mode: H (Rising) >
Trigger (alarm) level
Dead zone level
< Mode: L (Falling) >
<Mode: Rising>
Trigger (alarm) level
•
The upper limit values within the mode range and the lower limit values out of the mode range are dead
zone level as well .
•
When the detected alarm drops below the dead zone level, alarm is cleared . (When the alarm is not
retained)
<Example>When measuring temperature, the level released after the alarm generated is shown below .
• H (Rising) setting: Setting value -0.3℃/0.3ºF
• L (Falling) setting: Setting value +0.3°C/0.3ºF
•
Dead zone is not provided for pulse signals .
CHAPTER 3 Settings and Measurement
Trigger (alarm) point
Dead zone level
<Voltage>
• Level setting value 1% of negative range
(1V range: Level setting value -0.01V)
<Temperature>
• Level setting value -0.3°C
<Mode: Rising>
<Voltage>
• Level setting value 1% of positive range
(1V range: Level setting value +0.01V)
<Temperature>
• Level setting value +0.3°C
Trigger (alarm) point
3-103