Maintenance; Ideal Operation For X-Ray Tubes - GE ERESCO MF4 Series Operating Manual

8

Maintenance

Warranty claims shall only be considered if maintenance instructions are fully
observed.
8.1

Ideal operation for X-ray tubes

These recommendations and instructions are based on our extensive operating experience
and describe correct conduct for the daily handling of X-ray systems and, in particular,
X-ray tubes. The consistent implementation of these instructions will help to ensure gentle
X-ray operation.
This section makes no claim to be complete, since the service life of an X-ray unit depends to
a certain degree on various operating conditions and, in particular, on the actual application.
Due to these various conditions, it is also impossible to specify an average service life for
X-ray units.
Installation:
Only trained personnel should carry out system installation. All relevant and suitable
installation measures must be observed.
Initial start-up:
Due to the transport and storage, the X-ray tube cannot be immediately operated for a
longer period. Since the gassing of molecules from the surface into the evacuated space of
the X-ray tube head occurs on a permanent basis and cannot be prevented, the vacuum
is continuously reduced in the X-ray tube.
As a result, the free molecules in the reduced vacuum are ionised when a voltage is applied,
and the tube cannot be operated up to the nominal output. The potential difference can
result in sudden flashovers in the ionising channel.
To increase the service life of the X-ray tube, regularly warm-up or condition the tube.
In a physical sense, warm-up or conditioning is a Getter process in vacuum during which
free molecules are bound to the inner surface of the tube. The result is an improved vacuum
quality factor.
Warm-up is practically an operating mode during which the tube voltage is gradually
increased. The cycle time is individually calculated for each step, according to the tube
type, the desired nominal voltage and the operating life of the tube.
ERESCO MF4 has three warm-up programs:
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-
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In the automatic warm-up program, the ideal operating values are automatically calculated.
Automatic warm-up specifically considers the operating life of the tube and calculates the
ideal warm-up procedure via the pre-selected target voltage.
The manual warm-up program is only available for trained service personnel.
The Extended warm-up contains three programs:
up to 160 kV, up to 200 kV and up to 300 kV
Copyright by GE Sensing & Inspection Technologies GmbH
08/24/2016
6. Edition, ID No.: 37020GB-F
Operating Manual ERESCO MF4 Type Series
Automatic warm-up
Manual warm-up (only for trained service personnel)
Extended warm-up (for brand new tubes (green tubes) and to condition tubes that
have been out of operation for longer period)
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