Hardware manual

4-18 Agilent 7500 Series ICP-MS Hardware Manual
4Maintenance
Sample Line Connector Block
The action of the peristaltic pump rollers on the pump tubing can generate
static electricity in dry atmospheric conditions. This can cause signal
instability/fluctuations under certain conditions depending on the type of
nebulizer used.
When this phenomenon occurs, the tuning window will show signal
fluctuations like those shown in the above figure. Sensitivity may also be lower
than normal. To confirm the drift is due to charging, allow the nebulizer to
free aspirate (assuming this is possible with the type of nebulizer used), which
will eliminate any charging since the peristaltic pump is not used. If charging
is confirmed, use the Agilent 7500 Sample Line Connector Block Kit to ground
the sample line. This is a neat and effective way to eliminate signal instability
due to electrostatic charging.
WARNING
Confirm that the drain is flowing. Check that the tube from the drain peristaltic pump
to the drain bottle is properly connected. You should see a regular pattern of liquid
and air as shown above.
Flow Direction
Air Waste Solution
(PeriPump)(Drain Vessel)
time
NOTE
The connector block may be left in place when the block is bypassed.
For on-line addition of the internal standard solution, see the “Internal Standard Tubing Kit”
Section.