Datex-Ohmeda Anesthesia Delivery Unit S/5, Technical Reference Manual

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Datex-Ohmeda ADU
C-80
Document No. 8502855
Leak tests for service purposes
These tests are for detecting leaks in specific areas of the ventilator and the bellows block. The test in
“Ventilator test (Test 1)” on page C-80, includes expiration and inspiration valves, flow measurement
unit, drive gas cylinder, bottle pressure line from the bellows block bottom plate to the chamber
pressure sensor and zeroing valve as well as PEEP support line and peep support valve in the same
way.
The test in “Test for circuit and monitor pressure sensor lines (Test 2)” on page C-80, involves the
pressure lines to the circuit and the monitor pressure sensors and their zeroing valves.
The purpose of the test in “Test for Bellows block and bottom plate leakage (Test 3)” on page C-81, is
to identify leakages in the bellows block and the bottom plate of the ADU for service purposes. The
following procedure is for testing the possible points of leakage in Auto ventilation mode.
Ventilator test (Test 1)
1. The ADU in power On
2. The gas inlets connected to the central outlets
3. Enter Pneumatics Control on the Ventilator diagnostic page and Operate the expiration valves
(EXP. and PEEP on the diagnostic page). Close them both.
4. Remove the bellows block.
5. Connect a pressure manometer (cuff pump) to the driving gas hole in the bellows block bottom
plate with a suitable connector. See the figure below.
6. Pressurize the volume with the cuff manometer up to 30 mmHg.
Figure 46 The channels in the Bellows Block bottom plate
7. Wait for a minute. A pressure drop of 2 mmHg in 10 seconds at 30 mmHg pressure corresponds
approximately 10 ml/min. leakage. Pressure can also be observed from the output of bottle
pressure sensor on the diagnostics page of the ventilator.
Test for circuit and monitor pressure sensor lines (Test 2)
1. Remove the bottom plate gasket.
2. Connect the cuff manometer to the circuit and to the monitor pressure hole of the bellows
bottom plate. See the figure above.
3. Pressurize the circuit lines to 30 mmHg.
NOTE: Do not apply too high pressure to the lines as it may damage the pressure sensors.
4.
A possible leakage can be detected by the pressure drop on the manometer or by the circuit
and monitor sensor values on the ventilator service menu.
Scavenging
Driving gas
PEEP support
bottle pressure Circuit and monitor pressure