13 Maintaining the NPD
To Check the NPD Leakage Current
Maintaining Your GC 225
To Check the NPD Leakage Current
1 Load the analytical method.
2 Turn Off the Bead.
• Leave the NPD at operating temperature
• Leave flows on or off
3 Show the detector output signal in Status.
4 Verify that the output (leakage current) is stable and < 2.0 pA.
The output should slowly drop towards 0.0 pA, and should stabilize in the tenths of a
picoamp. Current > 2.0 pA indicates a problem.