Fluke Biomedical 76-810 - Manual (Page 7)

Test Procedures
Intrinsic Resolution
2
2-1
Section 2
Test Procedures
2.1 Intrinsic Resolution
1. Adjust the window position and width for the radionuclide for which the resolution is to be
measured. A good starting point is 1.5 FWHM. The count rate should not exceed 10,000 cps to
avoid any spectral shifts due to pulse pile-up.
2. With the collimator removed, install the appropriate test pattern against the face of the crystal, using
the adapter plate.
3. Raise the detector to its maximum height, at least 5 feet from the floor (see Figure 2-1).
4. Place a point source or vial of activity of the desired nuclide on the floor, and center it under the
detector. Select the activity of the source to produce a count rate of less than 10,000 cps. Use
appropriate shielding, making sure the source is able to see all of the crystal.
5. Accumulate an image consisting of 1 million counts for standard field cameras and 2 million counts
for large-field cameras.
6. Process the data or develop the film, and inspect the final image.
Figure 2-1. System Resolution
Figure 2-3. System Resolution with
Scattering Material
Figure 2-1. Intrinsic
Resolution