GE Alpha RT 32551 - kV, mAs and Exposure Time Test

5 Setups, alignments and adjustments
32551-IMG rev 6 GE Healthcare 73
5.2.9 kV, mAs and exposure time test
The measurement must be performed with a calibrated RTI, PMX-I/M or
equivalent.
1 Go into service mode when performing the test. Select manual
mode.
2 Attach cassette tunnel when measuring the LF. The Syncro Bucky
feature interrupts the x-rays for 50ms at grid turnaround points. The
interruption interferes the measurement.
When measuring the SF, no cassette holder should be used. Set the
parameters as shown in the table below and make the exposures.
3 Record the kV, mAs and time reading after each exposure. The time
reading is to be compared with the Alpha RT control panel time
display.
The maximum tolerance for kV, mAs and exposure time are:
For kV
± ( 1.5 kV + instrument inaccuracy) =
± ( 1.5 kV + 1.5 % of reading + 600V)
For mAs
± 4 mAs for mAs values less than or equal to 40 mAs
± 10 % for mAs values greater than 40 mAs
For exposure time
± ( 0.1 second + instrument inaccuracy ) =
± ( 0.1 second + 0.25 msec + 0.5 % of reading
kV adjustment
kV can be adjusted from R 63 located on the Inverter Board. See
figure 4.10, Inverter board.
kV mAs kV mAs kV mAs
LF 23 300 28 125 35 63
SF 28 63 35 20
Table 5.6 Parameters for small and large focuses