Thermo Scientific 7451 Operating And Maintenance Manual page 27

Section 2
Set-Up and Operation
Sample Thermocouple
Open (continued)
2-14 Controlled Rate Freezer
Run Mode
If the Sample probe fails and a freezing profile which does not reference
the Sample temperature is selected:
• Audible alarm sounds continuously,
• Alarm indicator flashes,
• Fourth line of LCD display shows "Sample sensor fail!" message,
• Sample temperature display shows "ILL".
The freezing profile will proceed normally. Pressing the Silence key will
mute the audible alarm, but the alarm indicator cannot be turned off and
the alarm message cannot be cleared from the fourth line of the LCD
display. The Sample temperature display will continue to show "ILL".
The Sample temperature display will revert to normal when the open
Sample thermocouple is corrected. Once resolved, pressing the Silence key
will turn off the alarm indicator and clear the alarm message from the
fourth line of the LCD display.
If the probe fails and a freezing profile which references the Sample
temperature is selected:
• Audible alarm sounds continuously,
• Alarm indicator flashes,
• Fourth line of LCD display shows "Sample sensor fail!" message
alternating with "Sample sensor requ." message,
• Sample temperature display shows "ILL",
• Switches to Idle mode and disables the Run key.
The audible alarm is muted by the first depression of the Silence key. The
Sample temperature display will revert to normal when the open Sample
thermocouple is corrected. Once resolved, the second depression of the
Silence key will turn off the alarm indicator, clear the alarm message from
the fourth line of the LCD display, and enable the Run key.
Thermo Scientific