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b. Go to the Drying Accessory screen, then select the PROGRAM button at
the bottom of the screen.
2. Select a program from the saved programs list or create a new program.
3. Press the START button.
4. The IN PROCESS LED indicator will turn ON.
Stopping a Program
1. At the end of the last programmed step, the tray dryer will turn OFF
automatically. The IN PROCESS LED indicator will turn OFF and a “Program
Complete” alert will be displayed on the touch screen. The collector and vacuum
systems will continue to run until they are turned off by the user.
2. To stop the tray dryer before the completion of the last programmed step:
a. Go to the Programs screen.
b. Select the program that is currently running.
c. Press the STOP button.
d. The IN PROCESS LED indicator will turn OFF.
3. Turn OFF the vacuum pump.
4. Position the Vac Release valve to OPEN.
5. Allow the vacuum to bleed to atmospheric pressure, then open the door and
remove the samples.
6. Turn OFF the collector, defrost the ice, drain the collector chamber and dry.
Setting the Operating Vacuum Level
To change the vacuum set point:
1. Go to Home screen
2. Press VACUUM:
Enter new vacuum set point value
Press APPLY (or START if vacuum pump is not already running)
The vacuum level may be set by the user to optimize the freeze dry process. Normally,
the sublimation rate will increase as the pressure increases in the freeze dryer. A good
starting place is to set the vacuum so its level is equivalent to about 10⁰C colder than
the eutectic or collapse temperature of the sample. The reference table below shows
the relationship between ice temperature and vapor pressure.
