Micromeritics Gemini VII 2390a, Operator'S Manual

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Gemini VII Preventive Maintenance
239-42828-01 - Dec 2012 9-7
Replacing the Sample Tube O-ring
It is important to maintain a vacuum-tight seal near the top of the sample tube stem. If an O-ring
becomes worn or cracked, it does not provide a good seal and will need to be replaced.
1. Holding the sample tube firmly with one hand, loosen the sample tube connector nut by turning
counterclockwise.
2. Carefully pull the sample tube down until it is free from the port. It may be necessary to grasp the
sample tube with both hands.
3. Remove the O-ring from the top of the sample tube and replace it with a new one.
4. After the new O-ring is in place, insert the sample tube back into the sample port until it is fully
seated.
5. Slide the sample tube connector nut up the tube (the ferrule and O-ring will move along with the
connector nut). Then, turning clockwise,
hand-tighten
the connector nut to the sample connector.
Before removing (or installing) a sample tube, ensure that the port valve is closed.
Observe the instrument schematic to verify valve status.
Be careful not to let the sample tube connector nut drop onto the bottom of the tube as
it may break the tube.
Be sure to use the proper size frit for the sample port. The instrument will not operate
properly if the incorrect frit size is used.
If the O-ring remains inside the sample port, use a pair of tweezers or needle-nose
pliers to remove it.
O-ring
Ferrule
Connector nut