LORAD AFFINITY Series, Service Manual

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P/N 9-500-0255 4-51
Service Manual
Chapter 4: Calibrations and Performance Checks
X-ray and Light Field Check and Alignment Procedures
7.7 7.5 cm Spot Contact Aperture Alignment (LG FS)
1. Loosen the screws securing the shield to the aperture. Insert the 7.5 cm Spot Contact
Aperture (Figure 4-12, Item 2) into the tubehead slot.
2. Set the exposure techniques Large focal spot, Manual, 25 kV and 100 mAs.
3. Make an exposure. Adjust the front edge of the aperture so the X-ray field aligns with the
markings on the alignment template and center the image side-to-side.
4. Tighten the four outer screws, securing the shield to the upper and lower aperture plates.
5. Verify the beam position again to ensure that the blades did not move when tightening
the hardware.
7.8 7.5 cm Spot Magnification Aperture Alignment (SM FS)
1. Loosen the screws securing the shield to the aperture. Insert the 7.5 cm Spot Magnifica-
tion Aperture (Figure 4-12, Item 4) into the tubehead slot.
2. Set the exposure techniques Small focal spot, Manual, 25 kV and 100 mAs.
3. Make an exposure. Adjust the front edge of the aperture so the X-ray field aligns with the
markings on the alignment template and center the image side-to-side.
4. Tighten the four outer screws, securing the shield to the upper and lower aperture plates.
5. Verify the beam position again to ensure that the blades did not move when tightening
the hardware.
6. Remove the alignment template when completed.
7.9 X-ray Field Alignment Verification
1. Install the X-ray Beam Alignment Template as per Section 7.1.
2. For each aperture (see Figure 4-12), make an exposure at:
3. 22 kV
4. 16 mAs
5. applicable focal spot
6. Develop the film.
7. For the auto aperture, check the film on the left, right, and rear edges for white space
(range: 1.0 - 3.0 mm). If the white space on the left, right, or rear edges do not meet
these specifications, re-adjust the auto aperture.
8. For all other apertures, make sure the exposure is centered.
7.10 Light Field Alignment Check and Adjustment
Remove the tubehead enclosures to access the Light Field Lamp and Bracket (refer to
Chapter 6: Maintenance—Remove and Replace Procedures). When making light field
adjustments, refer to Figure 4-14.
1. Install the auto aperture (refer to Figure 4-12) into the tubehead slot.
2. Select the Large focal spot, then adjust the lamp so that the light field is congruent with
the x-ray field (i.e., light field edges fall within 24 x 30 cm markings on template) as fol-
lows:
A. Longitudinal Position: alignment of front and rear edges. Loosen the screws
(Figure 4-14, Item 1) and rotate the lamp clockwise to move the Light Field
area forward (towards the patient); rotate it counterclockwise to move the
Light Field area toward the C-arm.