User`s guide

Routine Maintenance

282

Under normal operating conditions, the filter disks do not require

changing. However, they must be changed if the packing of the cold

trap has been overheated or has moved, or if chromatographic

problems have been observed (such as tailing peaks, sample loss or

sample carryover). You must always replace filter disks when

repacking the trap.

To change the trap filter disks:

1. Disconnect the ATD/TD from the AC line power. Allow

the system to cool. After the instrument has cooled, turn

off the purge gas supply (both carrier gas and dry air).

2. On the TD, open the front door. If you have an ATD,

you need to remove the front plate. Loosen the two

screws on the side of the instrument to release the front

plate and then gently pull the plate up and out.

3. Remove the heated valve cover. You will need a 7/64

Allen key.

4. Using wrenches loosen the fitting on the end of the trap.

Disconnect the fitting from the union and remove the

cold trap.

NOTE: Using wrenches, first loosen the trap nut at the left end of

the trap. Then remove the gas connections at the right end.

Slide the trap to the right to remove it from the peltier

cooler box. Exercise great care. Any torque applied to the

glass tubing could cause it to crack.

CAUTION

Always have a replacement trap available in case of

breakage.

CAUTION

Ensure that the GC oven and the detector are cool. If Ms is

used, the GC-MS transfer line and the Ion source must be

cool. The filament is also off.

WARNIN

The heated valve cover and the oven can be hot. Wait for 20

to 30 minutes for them to cool.