e. Select the next lower time.
(1)
Determine if the overload indicator activates on the first time station.
(2)
Decrease the time until the overload indicator deactivates.
(3)
Record the results on the form.
f. Repeat steps a through e with a large focal spot.
g. Repeat large and small focal spots at 60 and 120 kVp.
11-4. EVALUATION AND INTERPRETATION
a. Compare:
(1)
Exposure time settings of the activating overload indicator.
(2)
Maximum exposure time on the tube rating chart.
b. Ensure that the exposure time is within the maximum allowed.
11-5. PREVENTIVE MAINTENANCE
Perform the x-ray tube protective circuitry test:
a. At the beginning of a quality assurance program.
b. At six-month intervals.
c. Following the installation of a new x-ray tube.
11-6. CORRECTIVE MAINTENANCE
a. Test the tube protector.
b. Call the service representative immediately to readjust the unit if the tube
protector allows exposure in excess of maximum.
MD0062
11-3