Mindray WATO EX-55Pro, Service Manual

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6-21
6.6.4 Check the Sensor Zero Point
NOTE

The zero point A/D value of the airway pressure sensor and PEEP pressure sensor
should fall within the normal range of 7432 to 16206.

The zero point A/D value of the inspiratory flow sensor should fall within the
normal range of 554 to 26457.

The zero point A/D value of the expiratory flow sensor should fall within the
normal range of 1392 to 19306.

The zero point A/D value of the built-in ventilator flow sensor should fall within the
normal range of 1699 to 16768.

If the zero point of the pressure sensor has an error, in ventilation status, the
baseline of the Paw waveform is not at the zero point and a great deviation occurs
between pressure control and measurement.

If the zero point of the inspiratory/expiratory flow sensor has an error, in
ventilation status, the baseline of the flow waveform is not at the zero point and a
great deviation occurs between TV control and measurement.

If the zero point A/D value of any sensor is outside of the normal range, it cannot
be corrected. The monitor board must be replaced.
Checking the sensor zero point is to check if the zero points of all the flow sensors and pressure
sensors inside the machine are within the normal range so as to determine if replacing the monitor
board is necessary.
To check the sensor zero point:
1. Turn off all fresh gases and position the Y piece connector in the patient circuit to the
air.
2. Make sure that the system is Standby. Select the [Maintenance] shortcut key →
[
Factory Maintenance >>
] → [
Diagnostic Test >>
] → [
Display A/D Channels >>
]
→ [
Ventilator >>
] to access the [
Display A/D Channels—Ventilator
] menu.
3. Make sure that the actual measured value of each sensor is “0” (zero). Record the zero
point A/D value of each sensor and judge if the zero point falls with the normal range. If
not, replace the monitor board.