Pressure Too High Check; Pressure Too High Check Evaluation - Agilent Technologies 1220 Infinity II LC User Manual

Table 32
Leaking seals or scratched plungers.
Leaking outlet valve.
Leaky damper.

Pressure Too High Check

This test checks the flow path for a blockage, and tries to identify the module
that is causing the blockage. If the blockage is in the autosampler, the test can
identify whether the blockage occurs in the needle or needle seat.
The pump and autosampler are necessary to run the Pressure Too High Check.

Pressure Too High Check Evaluation

Start Conditions
The pump and autosampler are brought to the READY state, and an operating
pressure of 200 bar is applied to the system.
The pump ripple is measured, and the start of the test is delayed until the
ripple is within the defined limits (typically 1 % of operating pressure).
Test Part 1
Part 1 of the test tries to determine in which part of the system the pressure
problem lies.
After the system has achieved the start conditions, the autosampler valve is
switched from mainpass to bypass, and the pressure slice is tested against a
limit.
If the limit is exceeded, the pressure problem lies in the autosampler;
otherwise, it lies somewhere in the rest of the flow path.
1220 Infinity II LC System User Manual
Third plateau negative (pressure drop > 2 bar/min
Test Functions and Calibration
Solvent Delivery System
Exchange the pump seals. Check the plungers
for scratches. Exchange if scratched.
Exchange the outlet valve.
Exchange damper.
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