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RaySafe i3 Installation & service manual – Troubleshooting
MEASUREMENT PERFORMANCE VERIFICATION
All dosimeters are delivered calibrated, with no need for re-calibration during their lifetime. See the radiological
specification in the accompanying
Instructions for Use
. If you want to check the measurement accuracy, we
recommend the following arrangement.
The purpose of this test is to verify the measurement performance of dosimeters using scattered radiation from
diagnostic X-ray units.
CAUTION:
Do not expose yourself to X-ray radiation.
Required equipment:
• Two PMMA phantoms or other scattering material, for example a bucket with water.
• Dosimeters for test
• Real-time Hub, Video Unit and display, for dosimeter readings
INSTRUCTION
1. Place one of the phantoms (simulating the patient) on the patient support. Use a large phantom or a bucket filled
with water.
2. Place the other phantom (simulating the staff) at the same height, but 1.5 m away from the first one.
3. Place the dosimeter at the staff phantom, centered on the side facing the patient phantom. Test one dosimeter at
a time.
4. Expose with a field fully covering the patient phantom, at 80 kVp set, 4 mA, for 60 s. Adjust the mA to get a dose
rate of above 1 mSv/h. The dose rate can also be increased by placing a larger (or several) phantom(s) to simulate
the patient.
5. Note the dose rate from the display. Repeat steps 1 – 4 with the dosimeters you want to compare.
1.
2.
3.
4.
Figure 23. Performance verification arrangement. 1. Patient phantom. 2. Staff phantom. 3. Dosimeter. 4. X-ray field.
NOTE:
Radiologic specification in Instructions for Use (separate document).