n. Final Test Switch Settings. At the end of this test procedure, be sure to set
the test switches as given in the following chart.
SW3-5 OFF (Beam-Right Operation)
SW3-5 ON (Beam-Left Operation)
o. Cassette Tray Adjustment. The collimator has been factory-calibrated
around a cassette tray which is calibrated at 500 ohms for an 11 inch (12 1/8 inch
outside) cassette. The 11-inch dimension represents exactly one-half of the 1K-ohm
cassette tray potentiometer. Check, and adjust if necessary, your cassette trays.
Consult the tray manufacturer's manual for adjustment procedures. The following is a
size vs ohms chart.
Ohms between pins 1-5 and 4-8
With tilting tables, the table and wall cassette tray potentiometers must be set
exactly the same. This is because there is only one SID adjustment in the
collimator for a given distance to either Bucky.
AUTOMATIC EXPOSURE CONTROL
Test the Expos-AID automatic exposure control (AEC) annually to see that it
meets the kvp range/optical density tracking specifications. If it does not, repeat the
recalibrated or there is a change in the screen-film combination used. Visually inspect
the Expos-AID cables for signs of wear. Check cable and PCB connectors to ensure
they are securely fastened.