Vacuum Break/Backfilling
To open the chamber door, the vacuum must be released. To release the
vacuum, move the Vacuum Release Control to the “OPEN” position and shut
off the vacuum pump by pressing the VAC button. The vacuum can also be
released more quickly by opening one of the sample valves.
Air enters the vacuum chamber through the Back Fill Port. When the sound
of air through the Back Fill Port is no longer audible, the chamber door is
ready to open.
To backfill the chamber with a gas, connect a cylinder of the desired gas to
the Back Fill Port. The port will accept 1/8" tubing. The bottle must be
equipped with a regulator set to 15 psi maximum. The gas can be metered
with the Vacuum Release Control and chamber pressure monitored with the
freeze dry system’s vacuum gauge. Allow the vacuum pump to run for a few
minutes while the gas enters to permit the back fill gas to surround the freeze
dried sample. When the vacuum pump is turned off, air will enter the system
through the vacuum break valve located between the vacuum pump and the
collector chamber.