BIRD MARK 7 - Pressure Relief Valve Calibration and Troubleshooting

7.0 CERAMIC SWITCH “CHATTER TEST”
7.4 Position the following controls as indicated:
m PRESSURE SELECTOR — full counter
clockwise (minimum).
m CONTROLLED EXPIRATORY TIME control
knob at the 12:00 o’clock position.
8.2 Remove APNEUSTIC FLOWTIME control
knob and secure cam stops at the 7:00 o’clock
and 5:00 o'clock positions.
m SENSITIVITY SELECTOR — full counter
clockwise (minimum).
m CONTROLLED EXPIRATORY TIME — full
clockwise (“OFF”)
mw MARK ZA PRESSURE/TIME CYCLED
SELECTOR — switch “OUT”.
m INSPIRATORY FLOWRATE — full counter
clockwise (maximum).
m Push hand timer rod “IN”.
7.2 Unit should now “chatter” at an even
rhythm. if the respirator fails to chatter or chatter
is uneven in rhythm, slowly rotate PRESSURE
SELECTOR arm clockwise to balance the
magnets.
8.3 Rotate valve stem counterclockwise until a 3
second apneustic time is obtained.
NOTE: This is measured from the moment the red
hand timer rod moves “OUT” until the exhalation gate
opens.
8.4 Lubricate the O-
ring on the retention
cap and install control
knob with index resting
above the 7:00 o'clock’
cam stop and secure
in place. (Fig. 38)
7.3 If the respirator still fails to chatter or chatter
is uneven in rhythm, it will be necessary to
remove the ceramic switch for cleaning.
8.0 MARK 7A — APNEUSTIC FLOWTIME
È 8.1 Insert test lung onto breathing assembly and
i . position the respirator controls as follows:
m PRESSURE SELECTOR at 20.
m SENSITIVITY SELECTOR at 20.
FIGURE 38
8.5 Recheck for 3 second APNEUSTIC
FLOWTIME with the control knob full counter
clockwise and less than .5 second delay in the
clockwise position.
NOTE: Broached vaive; fine adjustments can be made
with a 752” allen wrench inserted in the end of the control
m INSPIRATORY FLOWRATE full clockwise. knob.
m PRESSURE/TIME-CYCLED SELECTOR ] - ーー
switch “IN”. 8.6 Rotate CONTROLLED EXPIRATORY TIME
control full clockwise “OFF”.
8.7 Troubleshooting APNEUSTIC FLOWTIME.
— 27 —
'4
NOILOAS
ONLLOOHSITSNOHL
ONY
NOILVHSTTYS