Agilent Technologies 6890 Series User Manual

Flow and Pressure Control Part 1. Electronic Pneumatic Control (EPC)
Maintaining EPC calibration
70
Maintaining EPC calibration
The EPC gas control modules contain flow and/or pressure sensors that are
calibrated at the factory. Sensitivity (slope of the curve) is quite stable, but zero
offset requires periodic updating.
Flow sensors
The split/splitless and purged packed inlet modules use flow sensors. If the
Auto flow zero feature (see page 33) is on, they are zeroed automatically
after each run. This is the recommended way. They can also be zeroed
manually—see the next page.
Pressure sensors
All EPC control modules use pressure sensors. They can be zeroed as a group
or individually. There is no automatic zero for pressure sensors.
Zero conditions
IMPORTANT Flow sensors are zeroed with the carrier gas connected and flowing. Pressure
sensors are zeroed with the supply gas line disconnected from the gas control
module.
Table 9 Flow and Pressure Sensor Zero Intervals
Sensor type Module type Zero interval
Flow All
Use Auto flow zero
Pressure Inlets
Packed columns Every 12 months
Small capillary columns
(id 320 µm or less)
Every 12 months
Large capillary columns
(id > 320 µm)
At 3 months, at 6 months, then every
12 months
Auxiliary channels Every 12 months
Detector gases Every 12 months

Agilent Technologies 6890 Series Specifications

General

Brand	Agilent Technologies
Model	6890 Series
Category	Laboratory Equipment
Language	English