Audible And Visual Alarms - Thermo Scientific Locator series Betriebshandbuch

Audible and Visual
Safety Feature
Level Monitor
Operation
Thermo Scientific
1. "LOW LEVEL" indicator light illuminates continuously when liquid
Alarms
nitrogen level is below the approximate 2" level. In this situation, the
level of liquid nitrogen is low, and you are alerted to refill the vessel as
soon as possible.
2. An AUDIBLE and remote alarm activates continuously when liquid
nitrogen is below the approximate 1" level inside the Locator or
Locator Plus vessel, additionally, "LOW LEVEL" light will continue to
flash. In this situation, the liquid nitrogen is dangerously low, and you
are alerted to refill the vessel immediately.
3. The AUDIBLE and remote alarms activate continuously, the 8-
segment LED display and "Low LEVEL" lights flash, to indicate an
emergency event. This alarm event occurs when the Locator or Locator
Plus vessel is empty of liquid nitrogen, or the monitor has an error and
is incapable of detecting LN2 levels.
The microprocessor must be reset each time the cover is removed from the
Locator or Locator Plus. Before removing the cover, the RESET button
must be pressed, illuminating the RESET light. While in this Reset/Hold
mode, the monitor is not sensing. After five minutes in the Reset/Hold
mode, an audible and remote alarm will activate, alerting you to deactivate
the Reset/Hold mode when the cover is replaced on the vessel.
Once the cover with the monitor has been placed on the vessel and
plugged in, wait about 15 minutes for the system to equilibrate before
pressing the Reset button for an accurate measurement of the liquid
nitrogen to be indicated. This equilibration process will occur each time
the cover is removed. Each time a vessel is opened or moved, the stabilized
chamber temperature and/or liquid level is disrupted. The system requires
a stable temperature and liquid level to determine an accurate liquid
nitrogen level.
If you have just purchased a new Locator or Locator Plus along with your
monitor, allow at least 1 day for the liquid nitrogen to equilibrate the
vessel before plugging in the unit. This will avoid false alarms.
Note The Level Monitor may take up to 10 minutes to establish a reading
after the unit is placed on the cryovessel, or the cryovessel is moved.
Remember to press "Reset" after placing unit on the vessel. The green
LED on the switch should be "OFF."
LN2 Level Monitor Operation
s
Cryogenic Storage Vessel
Section 6
6-5