Specifications

Total Added Filtration, mm Al
Below
50 kVp
50 - 70
kVp
Above
70 kVp
0.5 1.0 1.5
1.0 1.5 2.5
1.5 2.5 3.5
2.0 3.5 4.5
The recorded data is plotted on semi-log graph paper (Examples A and B, Fig.
5-6) and the half-value is read directly from the graph.
D. VERIFICATION OF COMPLIANCE
Verify that the half-value layer of the useful beam for a given X-Ray tube
potential is not less than the values shown in table 5-1.
NEMA Standard 5-15-1979
DOTTED LINE REPRESENTS
PERIMETER OF LIGHT FIELD
EDGE OF THE AND CORRESPONDS TO
X-RAY FIELD OUTER EDGE OF METAL
STRIPS
L1
W2
W1 IMAGE OF METAL STRIPS
L2 = 0 ONLY IN
THIS EXAMPLE
EDGE OF DIRECT PRINT - PAPER
FIGURE 5.3 LIGHT FIELD vs. X-RAY FIELD ERROR MEASUREMENTS
November 2005 ( 5 - 7 ) Linear MC150-C Collimator