Spellman LORAD LPX-200, Руководство оператора

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LPX-200
Industrial Imaging System
5-2
Chapter 5: LPX-200 X-ray System Operation
X-RAY TUBE WARM UP
The X-ray tube provided with the LPX-200 has been pre-aged
by the original manufacturer, and further tested and aged by
LORAD. It is necessary, however, to run the voltage up to the
required kV level at a fixed rate when the equipment has not
been used for a period of time.
The LPX-200 incorporates an AUTOWARM feature, which
permits the user to select and initiate one of five automatic
warm-up sequences. An AUTOWARM sequence is required
whenever the x-ray system:
◆
is to be operated above 100kV
◆
has not been operated at the required kV level for the
next exposure for 4 hours
◆
has a new tube with less than ten hours of operation
The AUTOWARM modes automatically set the run-up level to
200kV. However, it is only necessary to run the x-ray tube to
the kV level required for the next exposure. Run the
appropriate AUTOWARM sequence until the kV advances to
the next level higher than required for the exposure, then
terminate the sequence. Tubes having been previously
operated, but not run over 100kV for 30 days or longer, must
be treated as new tubes.
Note that for ALL AUTOWARM modes, detected tube
instability (as might occur with a new tube) causes the system
to automatically terminate x-ray generation. The Message /
Mode LCD will display an error (FAULT ARC RESTART),
which will require the user to re-activate x-ray generation.
The kV will then rise to a level 20kV below where the fault
occurred and operate for two minutes. After two minutes, the
kV advances to the next highest incremental kV level on the
selected warm-up schedule, and the AUTOWARM sequence
continues normally from that point.
The five AUTOWARM sequences are detailed next.
Autowarm Sequence : > 30 Days
The following procedure outlines the steps to “ run-up ” the kV
to the level required for the next exposure in cases where the
unit has not been operated for 30 days or more.
1. Prepare the x-ray system for the warm-up sequence:
❏
Turn the anode shield to completely block x-ray port.
❏
Close all interlock connections, or install the jumper
on the INTERLOCK connector.
❏
Place the MAINS circuit breaker ON.
! WARNING !
Although the window is blocked, do
not approach the Tubehead during
the warm up process. Observe all
applicable safety precautions and
survey the area to assure adequate
radiation limits.
2. Begin the AUTOWARM sequence:
❏
Select AUTOWARM : > 30 DAYS by pressing the
SCROLL button.
❏
Clear all unauthorized personnel from the area, and
activate all warning devices.
❏
Press the X-RAY ON button to begin the
AUTOWARM sequence.
! WARNING !
The system will now generate x-rays.
Observe ALL safety precautions.
Upon activation, the kV level rises to 100kV and the mA rises
to 5.0mA. After 2 minutes at this level, the kV automatically
increments 5kV. This slow
“ ramp up ” sequence continues
automatically until 200kV is reached (or until terminated by
the operator or by a fault), then automatically terminates x-ray
generation.
The LPX-200 is ready for use, as indicated by the prompt on
the Message / Mode LCD:
OPERATE: X-RAY READY .