Chromatographic Troubleshooting
Electronic pressure control
Electronic pressure control
The electronic pressure control option provides very accurate and precise control of column head pressure, resulting in retention time reproducibility of better than 0.02% RSD when there are no column effects. The inlet pressure can be set constant, programmed, or set to maintain a desired column flow rate. This mass flow control can be maintained even at vacuum column outlet pressures. A safety shutdown feature stops the run and can trigger an alarm if the column breaks or pressure otherwise falls. In addition, a bypass flow maintains a small positive column pressure in the event of power failure, protecting the analytical column.
Electronic Pressure Control Problems
Symptom | Possible Cause | |
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Not enough pressure | 1. | Septum leaks or is missing |
(Safety shutdown activated) | 2. | Column is broken |
| 3. | Column ferrule seal leaks |
| 4. | Gas supply is off |
| 5. | Supply pressure is inadequate |
| 6. | Desired pressure may not be achieveable with |
| the column in use. | |
Pressure goes to O or max. | 1. | Configuration is wrong. See the section Proper |
|
| configuration. |
Not Ready light flickers | 1. | Septum and/or column connection leaks. |
(oscillating pressure) | 2. | Pressure set higher than the operating limit |
Pressure not controllable | 1. | Configuration is wrong. See the section Proper |
|
| configuration. |
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If you have checked these possible causes and still have a problem, call HP Service.
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