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Issue date: 17 November 2006
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completed successfully (see image right).
(b)
Leak test – fail
. This flashing icon indicates that the leak test was not
satisfactory and the BA set did not pass the test (see image right).
•
Purge remaining air by operating the additional flow button.
•
Check the cylinder connection is hand tight and the LDV is connected to the
face mask correctly.
•
Undertake a second leak test – If the BA set fails the leak test a second time it is to be taken off
the run and sent to OSG workshops.
Note:
the ’set passed’ icon will remain displayed for up to three minutes, during which time the
breathe down sequence should be completed. If the breathe down sequence is not completed
the Bodyguard will display an ‘X’ icon, emit five audible ‘bleeps’ and then restart the ‘self-check’
if left the final icon displayed will be ‘operational mode’.
The timing out of Bodyguard would
necessitate the leak test being repeated. Re-open the cylinder valve and repeat testing from
section 20.63).
’B’ test: breathe down sequence
20.72
Open the cylinder valve slowly and fully.
20.73
Disconnect neck loop retaining stud, ensure all head harness straps are fully loosened and don
face mask, drop the head forward into the face mask placing the chin firmly into the chin cup.
20.74
Position the head harness over the head, locating the harness centre plate square on the back of
the head. Ensure that hair does not compromise the face seal area.
20.75
Tighten both lower straps together, and then the middle straps, ensuring all the straps are pulled
evenly towards the back of the head, keeping them evenly tensioned and in line with the mask
tongues. Check and if necessary tighten the top strap. The face mask should fit securely but not
be over-tightened.
20.76
Breathe normally.
20.77
Test the constant flow of air to the face mask by briefly operating the ‘additional flow’ button on
the front of the LDV once only.
20.78
Take a deep breath and hold, do not move head. Listen for any leakage from the face mask for
approximately 8 seconds and then breathe normally. If any leaks are detected from the face mask
readjust to fit and retest. If after readjusting the leak persists, get another wearer to try the mask
to ensure it’s the mask and not the wearer that is causing the leak before removing the BA set
from service.
20.79
Take a deep breath and hold,
close
the cylinder valve,
continue to hold onto the valve
.
20.80
Take hold of the Bodyguard in other hand and observe the display for
approximately 8 seconds whilst moving your head slowly up, down and side-to-
side to ensure the face mask is not leaking outwardly (positive pressure), this will
be noted by an excessive fall in pressure shown on the Bodyguard display.
20.81
After 8 seconds slowly breathe down the contents.
