Thermo Fisher Scientific CryoExtra CE8100 Series
Operation | 41
1.
Press “SETUP”
Controller will prompt for a
password. A flashing cursor will
make it clear which digit is being
changed. Use the “
” keys to
scroll to the appropriate number.
Press “ENTER” to advance the cursor to the next position.
2.
Press “ENTER”
The display will read “Temperature
Menus”.
3.
Press “SETUP”
Until the display reads “Liquid
Level Menus”.
4.
Press “ENTER”
The display will read “High Level
Alarm”.
5.
Press “SETUP”
Until the display reads “Advanced
Level Menus”.
6.
Press “ENTER”
The display will read “Auto Fill
Control.
7.
Press “SETUP”
Until the display reads “Level
Calibration”.
8.
Press “ENTER”
The display will read “Please wait
while the sensor zeros”. Wait for
the Controller to count down from
60 seconds.
9.
Wait 60 seconds
After the Controller counts down,
the display will read “Actual Level”.
Use the “
” keys to input the
meter dip stick measured level.
10.
Press “ENTER”
The display will read “Level
Calibration Complete”.
11. Verify that the home screen reads the liquid level value
that was just entered. In some cases the Controller
should be restarted. Contact Technical Support with any
questions.
Hot Gas Bypass Sensor
Calibration
This section describes how to calibrate the Controller hot gas
bypass sensor. There are two calibration procedures: single
point and two point calibration.
For single point calibration, the reference point is LN
2
. For two
point calibration, the reference points are LN
2
and ice water.
Unless regulations require a two point calibration, the single
point calibration procedure is recommended.
All new freezers have been calibrated at the factory. The hot
gas bypass sensor should only be calibrated if faulty readings
are suspected, bypass sensor has been replaced or as a part
of a preventative maintenance schedule.
For an accurate calibration, the LN
2
Saturation Temperature
(Section
“Liquid Nitrogen Saturation Temperature”
)
needs to be correctly set based on the altitude of the freezer
location.
Both the single and two point calibration procedures require a
small volume of LN
2
; enough to completely submerge the
bypass sensor. The two point calibration also requires an ice
water bath. Proper ice water bath preparation is imperative to
ensure accuracy. It is best to add filtered water to a Styrofoam
cup containing crushed ice. Allow the solution to stand at
room temperature for five minutes prior to beginning the
calibration procedure.
Note:
Security Level 2 or higher is required to calibrate the
bypass sensor.
Hot Gas Bypass Sensor Removal
1. Ensure all LN
2
supply sources are shut off and
disconnected.
2. Remove plumbing shroud or rear panel to access the
plumbing assembly.
3. Locate the hot gas bypass sensor on the plumbing
assembly.
4. Using a 9/16" or small adjustable wrench, remove the
sensor from the plumbing assembly. It may be necessary
to temporarily disconnect the sensor from the wire
harness to avoid over twisting of the wires. Following
removal of the sensor, reconnect the sensor wires.
Higher User Level
Required use
to
ENTER Password 0000
Press ENTER for
Temperature Menus or
press SETUP for next
menu
Press ENTER for
Liquid Level Menus or
press SETUP
for next menu
High Level Alarm 8.0 in
use
to
adjust
Press ENTER to save
Press ENTER to
Advanced Level Menus
or press SETUP
for next menu
Auto Fill Control
ENABLED Use
to
adjust Press ENTER to
save
Level Calibration
Press ENTER to Start
Calibration or SETUP
for next
Please wait while the
sensor zeros 60 seconds
Actual Level 10.0 in
Use
to
adjust
Press ENTER to save
Level Calibration
Complete
CAUTION
: Removing the hot gas bypass
sensor while a LN
2
supply is connected to the
freezer will cause the user to be exposed to LN
2
.
Before beginning procedure, shut off and
disconnect all LN
2
supply sources. Always wear
protective gloves and face shield when handling
LN
2
. Refer to the
section
of this manual.
