The System Pressure Test is used for checking the tightness of the LC system and identifying leaks between the pump and a position in the flow path following the pump blocked by a blank nut.
Minimum software revisions:
Lab Advisor B.02.08
Minimum firmware revision: D.07.01.
A solvent can be chosen from available solvent channels and a maximum pressure can be defined at which the test will be run. In contrast to older revisions of this test, any solvent can be used.
Before the test, the pump and system are flushed with solvent in order to remove air bubbles, as air bubbles are compressed during the test and therefore would appear as leaks. Using a degasser is highly recommended. Then the flow path is blocked by a blank nut at any position between the purge valve and the column outlet.
In the first phase of the test, the pump delivers flow at a rate of 200 µL/min until a pressure of 50 bar below the defined maximum pressure is reached. In the second phase, the pump delivers a small flow which is increased stepwise. If there is a leak in the system, the pressure will drop initially, as the low flow cannot compensate the leak flow. As soon as the pump flow rate exceeds the leak flow rate, the pressure will increase again and the test is stopped at about 20 bar below the maximum pressure. The point in phase 2, where the lowest pressure is reached and stays constant for a short time corresponds to the leak rate, that is provided as a test result. A leak rate smaller than 3 µL/min is good enough for operating the pump reliably.
base-id: 3820544651
id: 9007203075285643-1