8-23
Radiation Output Test
It is recommended that a check of the kVp(eff) and Radiation Output
of the X-ray source be performed annually by a qualified Physicist.
The incident Absorbed Dose at the detector may be measured using
a dosimeter. Tests are performed to assess output value and to check
for tube output consistency and timer accuracy.
1. Attach a dosimeter to the detector such that the sensor is
positioned where the vertical (coronal) and horizontal (axial)
lasers intersect.
2. Perform a standard 8.9 second, 8.5 diameter,14 cm, 0.4 voxel
scan and record time and dose from meter.
Measured Dose
The table below shows measurements performed on the detector for
a Landscape mode standard scan.
Tube Potential (kV) 120
Selected Scan Time (seconds) 8.9
Number of Frames 309
Approximate Exposure Time (seconds) 5.7
Displayed mAs 28.52
Measured Exposure at Detector (mR) 325.5
Measured Exposure at Detector / mAs (mR/mAs) 11.41
Measured Exposure at 1m (mR/mAs) 5.28
Measured Dose at 1m (μGy/mAs)
46.23
Dose at Detector per Frame (μGy/fr)
9.23
Tube Output (μGy/mAs @ 1m)
46.23
Distance Source to Detector (cm) 68.0
Conversion Factor for Absorbed Dose (R to Gy) 0.00876
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