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DONNING
18
P/N 595390-01
Rev D
202009
10
Smooth the head harness down the back of the head and make sure
the net is flat against the head. If necessary, adjust the bottom of
the head harness to sit below the crown of the head. See
11
Verify that the head harness is centered on the crown of the head
and lying flat against the back of the head.
12
Again, use the hand hold at the bottom of the netting to pull the
head harness down the back of the head. Pull forcefully enough that
the facepiece moves up to position your chin snugly within the chin
cup and forms a close fit to your face.
Figure 3-8 Adjusting the head harness
13
Once again, verify the proper location of the face in the facepiece
and the chin in the chin cup.
14
Re-tighten the straps. All straps must be snug and the facepiece
Figure 3-9 Verifying facepiece positioning
15
Perform a personal check of the facepiece and head harness and address any donning problems. If possible,
have a partner verify that you have donned your facepiece properly or use a mirror to check.
Possible facepiece donning problems include the following (see
):
•
Head harness strap is twisted.
•
Head harness is off-center or not flat against the head.
•
Head harness is too high on the head.
•
Hair or clothing is in the faceseal.
•
Face seal is rolled over inside the facepiece rather than flat against the face.
•
Facepiece sits too low on the face as evidenced by pressure on the forehead or the facepiece contacting
the throat area, permitting a break in the seal.
Similar conditions can occur with other facepieces as well. Verify that the facepiece is donned correctly regard-
less of the head harness style. If any donning problems are found, remove the facepiece and re-don the
facepiece correctly.
16
Perform a negative pressure User Seal Check by covering the facepiece docking port with your hand and
inhaling gently. If you feel the facepiece collapse slightly and pull closer to your face with no leaks between the
face and the facepiece, a proper seal has been obtained. If faceseal air leakage is detected, reposition the
facepiece on your face and/or readjust the tension of the straps to eliminate the leakage and recheck the seal.