8
5. Rotate the transducer until the image displayed is positioned in the horizontal
plane. This is the slice thickness of the sound beam at a given depth.
Note: For sector imaging systems, the beam will sweep back and forth as it passes
through the scattering plane, imaging the cross-section of the beam. In a multi-
transducer sector scan head the image will be the integrated sum of all the slice
thickness. To examine the slice thickness of the individual transducers, the frame
rate must be decreased permitting a single slice thickness to be displayed. De-
pending upon the system, it may be necessary to reduce the frame rate to zero.
6. Freeze image.
7. Using the electronic calipers, measure the distance from the scan surface to
the center of the displayed slice thickness image.
8. Again using the electronic calipers, measure the thickness of the image. This is
the slice thickness of the sound beam at a given depth.
9. Obtain a hard copy and document all measurements on the quality assurance
record
10. To obtain a series of slice thickness measurements at various depths, slide the
transducer along the scan surface. Repeat steps 4 through 9.