User`s guide

Operation

127

During primary desorption, the carrier gas will flow through the

sample tube from the bottom to the top. It is therefore essential that

sample tubes are loaded with their sampling ends (grooved end

)

upwards

. This will ensure that the volatiles are desorbed from the

collection end of the sample tube and do not pass through the whole

length of the adsorbent bed.

Sample tubes with pen clips may be loaded onto the TD. The tube

must be placed into the TD with the pen clip facing back, toward the

back of the instrument.

To load the tube:

1. Remove both caps from the tube. Ensure that the

instrument is Ready.

2. Place the tube into the tube compartment with the

sampling end (grooved end) upwards.

3. Center the tube in the lower, mobile seal and push down

on the seal with the tube. Gently push the tube in and

center the tube below the upper seal while it is seated

and then release the tube.

4. Press the Seal Up button to raise the tube into the

mobile seal.

5. Press Start.

6. Once the tube has been sampled, the display status will

be: Cooling. Do not touch the tube while this message is

displayed. The tube will still be hot from the desorption

process.

7. When the instrument status changes to Ready, press the

Seal Dwn button. The Mobile Seal with the tube will

move down and the tube can be released.

WARNIN

Ensure that sample tubes are cool before handling them.