Figure: 25 TAC §289.227(k)(4)(A)(i)

TABLE II - HALF-VALUE LAYER FOR SELECTED kVp
X-ray Tube Voltage
(kilovolt peak)
Minimum HVL
(mm of aluminum)
Designed
operating
range
Measured
operating
potential
X-ray systems
manufactured before
June 10, 2006
X-ray systems
manufactured on or after
June 10, 2006
Below 51 30 0.3 0.3
  40 0.4 0.4
  50 0.5 0.5
51 to 70 51 1.2 1.3
  60 1.3 1.5
  70 1.5 1.8
Above 70 71 2.1 2.5
  80 2.3 2.9
  90 2.5 3.2
  100 2.7 3.6
  110 3.0 3.9
  120 3.2 4.3
  130 3.5 4.7
  140 3.8 5.0
  150 4.1 5.4