Midmark Preva - Page 42

Preva Dental X-ray System User Manual, 00-02-1576, Revision ZA1
42
2(l)
Recommended loading factors for each patient size: refer to the System Configuration
section on page 26.
2(o)
The operating range and the maximum deviation for any setting within the operating
range for each loading factor are summarized below:
Factor
Nominal Value
Deviation
Peak Tube Potential
60kV, 65kV, 70kV
±5%
Tube Current
4mA, 5mA, 6mA, 7mA
Note: 7mA is not
available for 70kV.
±20%
Exposure Duration
min 20 ms, max. 2 s
±5% of 20ms, whichever is greater
2(q)
Removable protective devices: the modular beam-limiting devices (BLDs) available for
use with Preva are described in the Product Description section on page 6 and listed
by part number in the Certified Components
section on page 8. Information on the
effectiveness of the BLDs is provided in the
Dose Information section on page 42.
Instructions for BLD replacement are provided in Technical Advisory Notice (TAN) 55-
60-004, available in the Midmark.com Technical Library.
3(a)
Shape and dimension of the exit field: the shape and dimension of the exit field is
determined by the size of the BLD. For a list of available BLD sizes, refer to the
Certified Components section on page 8.
3(b)(ii)
Nominal X-ray image receptor air kerma range that is needed for the intended use:
refer to the Dose Information section on page 42. For dose administered when using
the ClearVision sensor, refer to the Dose Information section of the ClearVision
Installation and User Manual (00-02-1663).
3(b)(iii)
Recommendations for typical loading factors at specified distances between the focal
spot and the skin of 20 cm to achieve the air kerma referred to in subparagraph (ii):
refer to the
Dose Information section on page 42.
3(c)
The method by which the distance between the focal spot and the skin can be
determined using the focal spot indicators is determined by the length of the BLD. For a
list of available BLD sizes, refer to the
Certified Components section on page 8.
3(e)(i)
For the air kerma at a given distance from the focal spot for every selectable
combination of loading factors, refer to the Dose Information section on page 42.
3(e)(ii)
The maximum deviation of the air kerma: refer to the Dose Information on page 42.