Chapter 3 Calibration
Revision W HF Series X-ray Generators - Service Manual
3-66 Quantum Medical Imaging, LLC
NON-AEC REPRODUCIBILITY VERIFICATION
1. Set the Dynalyzer (or equivalent) for 75% trigger level on kVp. Ensure that
the meter is set to measure mR.
2. Set the generator Operator Control Panel to Manual mode, 45 kV, 100 milli-
seconds exposure time, Normal Density.
3. Using Table 3-9 below, locate the model number of this generator and set the
Operator Control Panel to the maximum mA setting shown in "SAMPLE 1 mA"
column (large filament), then take 10 consecutive exposures recording the
measured mR values in Non-AEC Reproducibility Data Sheet Table 3-10.
4. After the tenth exposure, select (coefficient of variation) COEFF VAR on Dyn-
alyzer; reading must be less than or equal to 0.05. If a Dynalyzer is not used,
calculate the C.O.V. (coefficient of variation) according to the following:
Table 3-9. Reproducibility Verification - mA Setting by Model
MODEL
SAMPLE 1
mA
SAMPLE 2
mA
MODEL
SAMPLE 1
mA
SAMPLE 2
mA
QG-20-SE 250 200 QG-40-2 500 400
QG-25 400 320 QG-40-3 500 400
QG-25-5 400 320 QG-40-SE 450 400
QG-32 500 400 QG-40-5 500 400
QG-32-2 500 400 QG-50 650 500
QG-32-3 500 400 QG-50-2 650 500
QG-32-SE 400 320 QG-50-SE 500 600
QG-32-5 500 400 QG-65 800 650
QG-40 500 400 QG-80 800 650
C =
Where
C= Coefficient of Variation
s = standard deviation
= Mean value of mR readings
x = i
th
observation sampled
n = number of observations sampled
x
i
=
s
X
1
1/2
n - 1
X
(x - x)
i
2
n
i=1