North 5500 series, Инструкция по эксплуатации и техническому обслуживанию, Страница: 11 / 167

3.1 TESTING FOR FIT
This respirator is available in three sizes; large, medium and small.
Most faces can be fit with the medium, however people with small
faces may get a better fit with the small size, and people with large
faces may get a better fit with the large size.
3.1.1 INITIAL FIT TESTING
A respirator should not be assigned to a person unless the person is
given a fit test and the results of the test indicate that the facepiece of
the respirator fits properly.
Fit tests should be conducted at least annually and sooner if there are
factors such as weight change or dental surgery which may affect the
fit of the respirator.
3.1.2 PERIODIC FIT CHECKS
Each time that the respirator is put on, before entering an area con-
taining hazardous atmospheres; and then periodically while wearing
the respirator in the contaminated area, the respirator wearer should
check the tightness of the seal of the facepiece to the wearer’s face
by carrying out a negative or positive pressure fit check. Readjustment
of the position of the facepiece on the wearer’s face and/or the ten-
sion of the headbands should be made if necessary.
3.1.2.1 NEGATIVE PRESSURE FIT CHECK
Place the palms of the hands over the openings in
the N7500-27 fit check/filter covers, inhale and
hold your breath for about 5 seconds. If the
facepiece collapses slightly and no air leaks
between the facepiece and the face are detect-
ed, a good fit has been obtained. If air leaks
are detected, reposition the facepiece on the
face and/or readjust the tension of the head-
bands and repeat the negative pressure
check until an effective seal is obtained (See
Figure 9).
FIGURE 9
Negative Pressure
Fit Check
10
GB