User guide

Detectors 10
Advanced User Guide 319
About the NPD
New NPD features and changes
The NPD firmware in this GC (A.01.08 or higher) is
considerably different from that in earlier versions and from the
6890 firmware. Major changes are:
• Equilibration time parameter has been removed.
• Adjust Offset feature has been changed.
• Auto Adjust on/off has been added.
• Dry Mode has been added.
• Blos/ceramic bead selector has been added.
We strongly recommend that you allow the firmware to perform
Auto Adjust and set the Bead Voltage.
NPD software requirements
This discussion assumes that the following firmware/software
is installed:
Software/firmware with numbers less than shown in the table
can cause reduced bead lifetime. See the Agilent web site
(www.agilent.com) for firmware and software updates.
NPD flows and general information
The NPD passes sample and carrier through a hydrogen/air plasma.
A heated ceramic or glass source, called the bead, is just above the jet.
The low hydrogen/air ratio cannot sustain a flame, minimizing
hydrocarbon ionization, while the alkali ions on the bead surface
facilitate ionization of nitrogen- or phosphorus- organic compounds.
Table 70 Software requirements
Product Software/firmware revision
7890A GC A.01.08 or higher
Agilent GC ChemStation B.04.01 or higher
Agilent MSD ChemStation G1701EA or higher
Agilent EZ Chrom Elite 3.3.2 or higher