User`s guide

Routine Maintenance
278
When specifying a Trap Clean method in a sequence, the method
must have a tube assigned to it. An empty tube is best suited for this
method. To perform multiple Trap Clean steps at the beginning of a
sequence, the Trap Heat method must be listed for a range of tubes.
De-Icing the Cold Trap
The dew point of the dry-air supply to the ATD/TD must be less than
–50°C. If it isn’t, severe damage may occur to the trap or the Peltier
cooler. Also, the ATD/TD may not be able to attain the trap low
temperature quickly or at all.
NOTE: We offer a dryer accessory that may be purchased. This
accessory will reduce the dew point to –50°C to prevent
icing of the cold trap.
Make certain that the dry air supply has a dew point of less than
-50°C. Use an indicating, moisture-removing filter to monitor the
dryness.
NOTE: The peltier cooler is ON from the time the instrument is
switched ON. Setting the trap temperature to a positive
value (e.g. +30°C) does not affect the temperature of the
peltier cooler, which is always at approximately -30°C.
To de-ice the cold trap:
1. Switch off the instrument and allow the Peltier and trap
area to warm up and the ice to melt.
2. Disconnect the instrument from the AC supply and
remove the cover of the trap compartment. See
Removing the Cold Trap on page 270.
3. Use paper towel to dry the area. Blow low pressure air
over the area to remove water droplets. If possible leave
the compartment open overnight.
4. Replace the cover plate. Ensure the flow of dry air has
been re-established, for at least 30 minutes.
5. Reconnect the AC supply and continue normal
operation.
CAUTION
Do not turn the instrument back on while liquid water is
present or you may break the peltier coolers.