Thermo Scientific 7451 Operating And Maintenance Manual page 38

Menu Entry
Definitions (cont.)
Thermo Scientific
a. Select Printer Output:
Select Chamber Only, Sample Only, Chamber/Sample Scan, or No
Printer (Off ). The default is Scan.
b. Enable/Disable Profile Set Temperature Line:
Turn On or Off a line on the thermal print-out that shows the set
temperatures and ramps as the freezing profile is run and printed.
The default is Off.
c. Previous Run:
A duplicate of the print-out made during the Run. The print-out
reflects the actual time and date of the run, rather than the current
time and date.
Note The unit will store at least 2 hours of data.
d. Select Printer Temperature Scale:
Select one of two printer scales; -180C to +50C (default) or -100C
to +50C.
e. Select Printer Time Scale:
Select 1, 2, or 5 minutes per division.
2. Probe Calibration:
Allows operator to calibrate the Chamber or Sample probes by entering
an offset and scale factor (scaler). Exit this menu by using the Back
key. Use an appropriate reference thermometer for comparison near
0°C (offset) and -196°C (scaler).
Note The chamber/sample limit temperature alarm will sound during the
scale factor adjustment at -196°C. Silence the alarm during the calibration
procedure by pressing the Silence key. Clear the alarm message after the
procedure is complete by pressing the Silence key one more time.
Important After calibrating the temperature probe,
reinstall the probe in the previous position. Make
sure the tape on the probe wire is flush with the
frame for consistent probe results.
1. Probe Offset:
The Chamber and Sample probe offset can be adjusted over a
range of -9.9°C to +9.9°C in 0.1°C increments. Adjust the probe
offset for a 0.0°C temperature display reading with the probe in a
standard crushed ice bath.
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Figure 3-1. Install Probe
Controlled Rate Freezer
Section 3
Configuration/Calibration
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3-3