Fluke Biomedical 4000M+ - Manual (Page 24)

Victoreen 4000M+
Operators Manual
3-6
1. Position the detector on the table with the black plastic disk facing down (toward the source of x-
rays).
NOTE
To eliminate measurement error due to the “heel”
effect, position the Model 4000M+ so that the front-
to-rear panel axis is parallel to the tube anode-to-
cathode axis.
NOTE
Align the BEAM DIRECTION arrow on detector’s
rear panel with the direction of the x-ray beam.
2. Using centering marks provided on the table (or another centering method), center the detector
over the x-ray beam.
3. Energize the fluoroscope to view the detector on screen.
4. Move the fluoroscope so that the lead shield containing detector diodes (opaque rectangle) is
centered in the screen.
5. For automatic brightness control machines, place the appropriate shielding (e.g., a folded apron,
gloves, or a lead sheet) over the detector to drive the output to its maximum. For manual systems,
set machine for maximum output and use the appropriate shielding to protect the image intensifier.
Other Applications
Follow the same basic principles of detector positioning for other applications. In general:
1. Locate the detector 46 to 102 centimeters (18 to 40 inches) away from the source of x-rays.
NOTE
To eliminate measurement error due to the “heel”
effect, position the Model 4000M+ so that the front-
to-rear panel axis is parallel to the tube anode-to-
cathode axis.
2. Point the black plastic disk toward the source and in the approximate center of the beam.
3. For chest x-ray machines, the unit can be taped or strapped to the table in front of the film cassette.
3.6 Displayed Results
As discussed in Section 2 – Operation:
• In the Radiographic Mode, displayed values include the average kVp, the effective kVp, the
maximum kVp, length of the exposure in seconds, and the tube output in Roentgens or Grays.
• In the Fluoroscopic Mode, displayed values include the exposure rate (in mR/min or mGy/sec) and
the calculated kVp value.
In addition to displayed values, the Model 4000M+ displays informational and error messages. Refer to
Table 3-1 for a description of displayed messages.