Heating The Ptv Inlet - Agilent Technologies 7890 Series Advanced Operation Manual

3
Inlets
Septum head
Septumless head
The flow diagrams in the rest of this document show the
septum head in place with a separate drawing for the
septumless head.

Heating the PTV inlet

The control parameters for PTV temperature programming
are the same as for the column oven, but are reached by
pressing [Front Inlet]. Temperature can be programmed with
an initial temperature and up to 3 rates and plateaus. Rates
between 0.1 and 720 °C/min can be selected. See "Setting
COC inlet parameters" on page 95 for details.
At the end of the run and during post- run, the PTV is held
at its final temperature. This permits backflushing without
contaminating the inlet.
If the initial inlet temperature and the oven initial temperature are
C A U T I O N
too close, the inlet may be unable to maintain its setpoint. We
recommend a difference of at least 6 °C, either higher or lower.
Additional temperature ramps
For most purposes, the PTV is designed to hold the sample
in the inlet liner until the entire sample—there could be
several injections—has been injected. Then the PTV is heated
rapidly to transfer the sample to the column. This can be
accomplished with an initial hold, a single ramp, and a hold
at the end to complete sample transfer.
Two additional ramps are available and have several possible
uses:
• The inlet can be heated to a high temperature to
thermally clean the liner for the next run.
Advanced Operation Manual 97