VOTI XR3D-6, Техническое обслуживание и устранение неисправностей

Страница: 38 / 94

XR3D-6 Maintenance & Troubleshooting
3-18 EM-XR3D-6-001-EN.D
©2011 VOTI Inc.
4. Record the location on the XR3D-6 if the value goes over 0.5 mR/h (milliRoentgens per
hour) measured 5 cm (Europe - 0.1 mR/h (milliRoentgens per hour) measured 10 cm ) from
any outside surface of the scanner.
External surface defines the edge of each component of the scanner. To measure the
entrance and exit of the scanner, the survey dosimeter must be placed at 5 cm from the
shroud’s edge and not at the drapes.
5. Press XRayOff in VOTI's Diagnostic Tool application.
6. After having followed all the steps, perform this procedure again with higher values of
voltage and current in the DIOX application. Values recommended by VOTI are:
o
Program voltage:160 KV (1600), Program current: 500 µA
o
Program voltage:160 KV (1600), Program current: 900 µA
7. Exit VOTI's Diagnostic Tool and the DIOX applications.
The LEDs on the XR3D-6 turn off.
8. File the completed report.
If there are any areas on the XR3D-6 that did not pass the test, forward the completed
Incident and Test reports to Level 3
– VOTI technicians at
support@voti.ca .
3.7 Calibration Test Procedure
To calibrate the XR3D-6, VOTI uses 3 step wedges; Plexiglas, aluminum, and steel. These
materials ensure an accurate linear regression, as the atomic values are within the material
specifications range. Other materials can be used, but VOTI recommends these materials at a
minimum. After the calibration matrices are computed they are automatically saved to the
c:\Program Files\VOTI\BioSansXDAQ/output/archive
folder.
To verify the calibration, use the step wedges and check for the atomic number. The same
atomic number should appear in the entire step wedge even if there are different thicknesses.
The calibration step wedges are each composed of one of three different materials which the
effective atomic number
is known:

Plexiglas

Aluminum -

Steel -
The number of calibration scans to acquire depends on how many are necessary to cover the
whole range of detectors. Usually, two scans are necessary per step wedge to cover the whole
area (width of the tunnel).