Planer Kryo550-16, Руководство оператора

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Pulse seeding
Long pulse durations can cause the chamber to overcool so this feature
should be used with care. When determining the appropriate time always
start with a very short duration, less than 5 seconds, and then experiment
with longer times until an appropriate duration has been found. The
suitability of this process for any particular freezing protocol requires
validation by the end user.
With pulse seeding, a seeding start temperature and pulse duration are defined in the profile.
When the
sample reaches the temperature defined by the seeding start temperature, the liquid
nitrogen valve is opened fully for the time defined by the pulse duration. This causes the
temperature in the chamber to fall very quickly. The sudden drop in temperature can be used
to initiate freezing in large samples such as bags. At the end of the defined duration, the
valve is shut and the heater is switched on fully to heat the chamber back to the normal
profile as quickly as possible. Once the chamber has returned back to the profile, the heater is
switched off and normal control resumed.
3-4 Freezing Samples
Sample freezes
Heater switched full on to
return to profile
Sample reaches
the seeding temperature
Seeding start
temperature
Pulse duration
Valve full on for
pulse duration
causing rapid
chamber cooling
chamber
sample
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time