Esco Lexicon - Set Temperature & Hysteresis; Product Loading Guidelines; Opening and Closing Doors

12
Temperature Stabilization Periods
- Startup – Allow 12 hours for the temperature in the cabinet to stabilize before proceeding with
calibration
- Already Operating – Allow at least 2 hours after the display reaches set point temperature to stabilize
before proceeding with calibration
3.3 Set Temperature & Hysteresis
The freezer is shipped from factory with temperature set point -80
o
C and hysteresis 1
o
C. The LCD screen will
blink between the first and the second display
Step
Action
Press
Display Show
First
Second
1
Press “P” key for 3 seconds (the second display shows
chamber temperature; eg: 15
o
C)
P
15
2
Set code 72 for accessing the parameter level by using the ▼
and ▲keys
▼and ▲

72
3
Press “P” key to set the temperature
P
4
Set the temperature value by using the ▼ and ▲keys (the
second display show set point temperature; eg: -80
o
C)
▼and ▲

-80
Press “P” key to set the hysteresis
P
6
Set the hysteresis value by using the ▼ and ▲keys (the
second display show set point hysteresis; eg: 1
o
C)
▼and ▲

1
7
Press “P” key to confirm
P

8
Allow some time for the instrument to switch back to the
process value display
3.4 Operating the Freezer
3.4.1 Product Loading
Loading of warm product into the freezer should be done in batches. Do not fill the freezer with product of
more than 25 percent of the volume at one time as this process might introduce too much heat load into the
freezer. Allow freezer to stabilize. Once the temperature of the freezer returns to the set point, another batch
of product can be loaded in.
Fill an upright by starting at the bottom near the probe and add products to racks to one shelf at a
time, allow freezer to recover to set point or temperature between shelves
Fill empty shelves with frozen water jugs, for example, to help overall performance
Always make sure the vacuum relief port is free of frost and ice, to allow for timely re-opening of the
main door.
ESCO ULTs are designed for long term storage. It is recommended that only pre-frozen products be placed in
the unit as that will reduce the amount of heat load that must be absorbed by the freezer at one time.
3.4.2 Opening and Closing Doors
Main door and inners doors should be closed tightly at all times. When taking the samples out, open the main
door and then open only one inner door at a time.