Villa Rotograph EVO, Руководство по обслуживанию

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SERVICE MANUAL
Technical data
(Rev. 1) Rotograph EVO 4-9
4.3. Measurement method of technical factors
WARNING:
These measurements require the removal of the HF group covers; this
means to gain access to internal parts where high voltage are normally
present.
For the measurement of the exposure parameters with the invasive
method, please follow the procedure described in paragraphs 7.3.1, 7.3.2
and 7.3.3 of this manual.
WARNING:
During the panoramic examination, the set value of kV and tube current
varies according to a pre-determined curve in order to compensate the
different absorption of X-ray beam due to different anatomical structures.
In this way, it is possible to obtain a good uniformity of the image
contrast. Particularly, the chosen value is lowered on the initial phase of
the panoramic and increased on the scissors/canine zone, in order to
compensate the effect of the cervical spine.
The value displayed during the panoramic examination corresponds to
the one chosen by the user, while the real value can be different; these
effects must be considered in case of measure of the exposure factors
using standard diagnostic mode. As an example, the variation follows the
curve hereafter:
Set value
Actual value kV
Actual value mA
Accuracy declared on the section "Technical data" is referred to the
actual value of kV and/or mA. In any case, the manufacturer guarantees
that the accuracy of loading factors is always compliance with the
international standard for safety of medical devices IEC 60601-1.
Particularly, in accordance with IEC 60601-2-7, the maximum deviation
(including the correction and instrument’s accuracy) is less than or equal
to
± 10 % for kV, while for tube current is less than or equal to ± 15%.