CETAC Aridus II, Руководство оператора

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Aridus II™ Operator’s Manual
Chapter 7: Troubleshooting the Aridus II™
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chamber. Turn off power to the Aridus II
™
and allow the spray chamber to
cool (15-30 minutes). Then unscrew the nebulizer port fitting and replace
with a new nebulizer port fitting (which has o-rings in place). The port
fitting is CETAC part number SP8015. See Figure 7-1.
Figure 7-1. Nebulizer Port with 2 O-Rings.
Sample flow rate problems
•
The liquid flow rate is too high. The self-aspired liquid flow rate is
determined by the nebulizer gas flow. Decreasing the nebulizer gas flow
will decrease the liquid flow rate. Consequently, signal intensity may
decrease as a result. Proper nebulizer gas flow rates should be optimized
based on each individual application. Normal criteria for assessing
performance are signal to background ratios and elemental oxide levels.
•
Liquid accumulation in spray chamber. Replace the peristaltic pump
drain tubing and adjust the pump shoe pressure to be slightly firm.
Inspect the pump tubing on a daily basis and replace as required,
especially when it becomes worn and flattened.
Poor precision
• Improper gas flows. Poor precision is often due to improperly set gas
flows. If the imprecision is characterized by large, periodic drops in signal
intensity, the cause may be an excessive sample flow rate. Poor short-term
precision can be caused by a non-optimum sweep gas flow.
•
Concentrated samples. More concentrated samples (>1% dissolved
solids) may also cause poor precision. In addition, such samples may
require longer rinse-out times.
•
Clogged or contaminated tubing. Finally, readjustment or replacement
of the peristaltic pump drain tubing may be necessary to improve
precision.