Mindray WATO EX-55Pro, Service Manual

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6-22
6.6.5 Check the Flow Sensor Accuracy
NOTE

If a great deviation of TV measured value occurs, test the measurement accuracy
of flow sensors so as to determine whether to perform flow calibration again.
Checking the flow sensor accuracy is to check:
 The measurement consistency between the flow sensors inside the machine;
 The measurement accuracy of any single flow sensor inside the machine;
 The validity of (factory) flow calibration result.
To check the measurement accuracy of flow sensors:
1. Make sure that the circuit, calibration device (or other flow measurement device) and
breathing tubes are connected in serial, similar to tubes connection in flow calibration.
For details, refer to
7.3.2 Flow calibration (Service)
.
2. When the system is Standby, select the [
Maintenance
] shortcut key → [
Factory
Maintenance
>>] → [
Diagnostic Test
>>] → [
Valves—Test Tool
>>] to access the
[
Valves—Test Tool
] menu.
3. Set PEEP safety valve to [
ON
].
4. Set the D/A value of the PEEP valve to above 1500 and ensure that the pressure at
which the expiratory valve closes is above 30 cmH2O.
5. Increase the D/A value of the inspiratory valve, causing the measured flow value of the
anesthesia machine calibration device to fall with the following ranges respectively:
(3±0.5) L/min, (10±1) L/min, (20±1) L/min, (30±2) L/min, (60±3) L/min. Record the
measured flow values of the inspiratory flow sensor, expiratory flow sensor and
ventilator flow sensor to which each setting corresponds respectively. When testing the
flow accuracy of (60±3)L/min, only compare the accuracy of the inspiratory flow sensor
and expiratory flow sensor. It is no need to compare the ventilator flow sensor.
6. Make sure that the deviation between the measured data of the inspiratory flow sensor,
expiratory flow sensor and ventilator flow sensor and that of the anesthesia machine
calibration device must not exceed 1 L/min or 5% of the measured value of the
calibration device, whichever is greater. Otherwise, refer to
7.3.2 Flow calibration
(Service)
to perform flow calibration again.
7. If anesthesia machine calibration device is unavailable, you can execute steps 1 through
5 to test the accuracy of flow sensors. The deviation between the measured data of the
inspiratory flow sensor and expiratory flow sensor and that of the ventilator flow sensor
must not exceed 1 L/min or 5% of the measured value of the ventilator flow sensor,
whichever is greater. Otherwise, refer to
7.3.2 Flow calibration (Service)
to perform
flow calibration again.