T.O. 33B-1-1
6-139
i. Refer any occupationally exposed individual who sustains an actual overexposure to the supporting
occupational health physician. (The occupational health physician in consultation with the RSO will
determine the appropriate medical examinations (if any) and plan appropriate medical care.)
6.9.15.4
(Army) Administrative Assessment of Dose.
If a dosimeter is lost or damaged or if the occupationally-exposed individual's TEDE or CEDE cannot otherwise be
determined, the RSO shall determine and assign an administrative dose pursuant to paragraph 4-13 of AR 40-14, and
report the assigned dose to the US Army Ionizing Radiation Dosimetry Center for inclusion in the individual's
permanent dosimetry file.
6.9.16
Standard Department Of Defense Industrial X-Ray Radiographic Equipment.
6.9.16.1
Lorad Model LPX-160A Portable Industrial X-Ray Unit.
The LPX-160A is an air or water-cooled X-ray unit with an operating potential of up to 160 kV and a tube current of
up to 5 milliamperes (mA). The tube head is insulated with sulfur hexafluoride gas, pressurized to 50 psig @ 70F, is
end grounded and has a 0.063-inch thick beryllium window (for beam filtration) located approximately 2 inches from
the end of the tube. At 0.5 meter from the window, the dose rate in the beam is about 240 R/min (2.4 Sv/min) and 14
R/min (140 mSv), unfiltered and filtered respectively through 0.5 inches of aluminum. The unit has a radiation cone of
40 degrees. Leakage radiation as measured one meter from the tube head, with the main beam being absorbed by 25
half-value layers of lead, ranged from 12.7 mR/hr (127 mSv/hr) to 385 mR/hr (3.85 mSv/hr). The measured half-value
layer (HVL) of 0.41 inches corresponds to an average X-ray energy of about 83 keV.
6.9.16.2
Magnaflux Model GXR7.6B/GXR7.6C 150-KVP X-Ray Unit.
Unit output is approximately 49 R/min (0.49 Sv/min) at one meter from the tube target with the tube operating at 150
kVp and 7 mA. The tube head assembly contains an end-anode ceramic-enveloped X-ray tube with a 0.03-inch (0.75-
mm) beryllium window for beam filtration. The unit has a radiation cone of 40 degrees. Maximum leakage radiation
is approximately 1.3 R/hr (13 mSv/hr) at 1 meter with the tube h-ad placed in a hori20ntal position and with the beam
port down and blocked by a ¼-inch lead sheet.
6.9.16.3
Sperry Model SPX 160-KVP X-Ray Unit.
The output of this unit is approximately 60 R/min (0.6 Sv/min.) at one meter from the tube target with the tube
operating at 160 kVp and 5 mA. The only filtration in the primary X-ray beam is that provided by the 0.092 inch (2.3
mm) beryllium window. The nominal cone of radiation is 40 degrees and the duty cycle is continuous with external
cooling. The end-anode type of X-ray tube is shielded with a 1/8-inch lead collar with a circular aperture for the
primary beam. Typical tube housing leakage radiation exposure rates range from 300 to 600 mR/hr (3 to 6 mSv/hr) at
one meter from the tube target. However, a cone of leakage radiation, ranging from 1 to 4 R/hr (10 to 40 mSv/hr) at
one meter and emanating from the high-voltage-input end of the tube housing at an angle of approximately 10-18
degrees with the major axis, may be detected with some units.
6.9.16.4
Sperry 275-KVP Unit.
WARNING
When surveying the cone of radiation leakage in the rear of the tube head of Sperry
units the survey instrument should be scanned from the floor toward the ceiling.
This will prevent the instrument operator from unknowingly entering the high
radiation area produced in this cone. Perimeters shall be established on the basis of
the highest reading obtainable at a given point.
The maximum output in the beam of a typical 275-kVp X-ray unit is 150 R/min (1.5 Sv/min) at one meter from the
tube target with the tube operating at 275 kVp and 10 mA. The beryllium window provides an inherent filtration
approximately equivalent to 0.1-mm aluminum. The nominal cone of radiation is 35 degrees and the duty cycle is
