Philips CARDIOMD, Service Manual

Page: 369 / 466

CardioMD AC Option
1MAN0158-H11 04-2005 CSIP Level 1
CardioMD Service Manual
„
12-21
Figure 12.19 Shutter position sensing
In case of a power failure or error condition, the spring automatically closes the shutter. However,
in case of faults you can close the shutter by pushing in the manual shutter knob. The shutter
cannot be opened by means of the knob.
When the shutter is open, this is indicated by:
•
The manual shutter knob is in the OUT position
•
The line source compartment’s built-in shutter status LED is ON (see Figure 12.14 on page
12-17).
Attenuator
When the Gd-153 source is fresh, the radiation from the line source must be reduced. However, as
the line source grows older, you will want to take advantage of its full radiation capacity. The line
source housing attenuator allows just that.
The attenuator consists of 4 copper strips that are mounted on top of each other in the line source
housing. When the line source is delivered from the manufacturer, all four strips are in place
covering the aperture of the line source housing. When the line source is growing too weak,
all
four strips are retracted from the aperture.
Caution . All 4 copper strips of the attenuator must be in the closed position
when the line source is new. Likewise, all 4 strips must be retracted and placed
in the open position when the attenuator is removed. For instructions, see
section 12.5.3.9, page 12-75.
CAUTION
Optocoupler detecting
shutter position
Shutter closed
Optocoupler detecting
shutter position
Optocoupler detecting line
source park position