Agilent Technologies 7890A Troubleshooting Manual page 108

8
Troubleshooting Tasks
To Measure NPD Leakage Current
108
1 Load the analytical method.
Set the NPD Adjust Offset to Off and the Bead Voltage to
2
0.00 V.
• Leave the NPD at operating temperature.
• Leave flows on or off.
Press [Front Det] or [Back Det], then scroll to Output.
3
Verify that the output (leakage current) is stable and
4
< 1.0 pA.
5 The output should slowly drop toward 0.0 pA, and should
stabilize in the tenths of a picoamp. Current > 2.0pA
indicates a problem.
Troubleshooting