Thermo Scientific CryoStar NX70 Operator Guide
76
Defrost
Inevitably, when working on the microtome the dry cold air of the Cryochamber mixes with the warm
humid air outside the chamber. Frost forms on the finned evaporator. The increasing thickness of the
frost reduces the efficiency of the evaporator. For this reason, the daily defrosting is necessary.
During defrosting, remove the specimens from the Cryochamber, as the temperature
inside the chamber will increase. Do not leave or store specimens inside the cryostat
over a long period of time. Due to a power failure or other unexpected malfunctions of
the instrument, the specimen might be damage.
Note
Set the time of the daily defrosting on the control panel. The period of the defrosting takes approximately 1
hour and varies according to the thickness of the frost.
Possible frost build-up on the microtome or on the knife carrier is not removed by defrosting the instrument.
However, the frost recedes after defrosting as now the evaporator is fully efficient again.
In addition, the instrument is equipped with an immediate defrosting function. The immediate defrosting
takes approximately 90 minutes.
Immediate Defrosting
To start the defrosting immediately:
•
Press the "Menu" button on the Main screen.
•
The Menu screen will be displayed.
•
Press the "Settings" button.
•
The Menu: Settings screen will appear.
•
Press the "Defrost" button.
•
The Menu: Settings: Defrost screen will be displayed.
