3. Have the wearer stand with the back of the head against the block. Ensure that the
wearer's posture and body alignment are as straight as possible. The wearer should hold
his or her head in a comfortable position while focusing on a point directly ahead at eye
level.
4. Referring to
Figure 2-2, View A
, use a ruler to measure a distance 1-1/2 inches above the
wearer’s pupil. Using a marker, make a small mark at this point in the center of the wearer’s
forehead; this is the
forehead reference point
(FRP).
5. Referring to
Figure 2-2, View B
, use a combination square to measure from the FRP to the
block; this is the
head length
. Be careful to just touch the wearer’s skin at the FRP.
6. Select the correct helmet size based upon head length as follows:
HEAD LENGTH (INCHES)
HELMET SIZE
> 8-5/16
XL
8-1/16 - 8-5/16
L
7-3/4 - 8
M
7-7/16 - 7-11/16
S
7-1/8" - 7-3/8
XS
< 7-1/8
XXS
6
VIEW B
VIEW A
FRP
Ruler
Marker
1-1/2 inches
Wood block
Combination square
Figure 2-2. Determining Head Length
Summary of Contents for HGU-56/P
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Page 72: ...66 Figure 4 2 Dual Visor Assembly Plain 2 3 1 11 7 9 4 5 6 10 8...
Page 80: ...74 Figure 4 7 ANVIS Direct Mount Dual Visor Assembly 1 11 7 9 4 5 6 10 8 3 2 12 14 15 13...
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