4-8.
EQUIPMENT/MATERIAL
a. Motorized synchronous top (mAs-timer test tool).
b. Lead blockers.
c. Timer protractor.
d. Extension cord.
e. A 10- by 12-inch cassette.
f. Lead numbers.
4-9.
PROCEDURE
a. Plug the timing tool into 110 volt outlet.
NOTE:
If needed, use an extension cord to ensure that the test tool can be easily
placed on the x-ray table.
b. Place the cassette on the x-ray table.
c. Place a lead blocker over three-fourths of the cassette, leaving one-fourth
exposed. Four different exposures are made on one cassette.
d. Place the timing tool on the unleaded portion of the cassette.
e. Collimate the x-ray beam to the test tool.
f. Set the SID at 40 inches.
g. Calculate the given mAs.
(1)
Use four different times and mA.
(2)
Examples:
(a) 50 mA at 1/5 second (see figure 4-7).
(b) 100 mA at 1/10 second (see figure 4-8).
(c)
200 mA at 1/20 second (see figure 4-9).
(d) 300 mA at 1/30 second (see figure 4-10).
MD0062
4-9