Mindray WATO EX-55Pro, Service Manual

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7.3.2 Flow calibration (Service)
NOTE

After the VCM or expiratory valve assembly is replaced, flow calibration (service)
shall be implemented.

If the deviation between the value measured by the embedded flow sensor and the
value measured by a standard flow measurement device is great, flow calibration
(service) shall be implmented.

When the altitude changes significantly, if the TV precision is out of range,
perform the flow calibration (service).
7.3.2.1 Flow Calibration Principles
In the automatic flow calibration, the anesthesia machine calibration device specified by the
manufacturer needs to be used to calibrate the inspiration valve, ventilator flow sensor, inspiratory
flow sensor, and expiratory flow sensor. The calibration principles are as follows: The anesthesia
machine calibration device can communicate with the VCM. The VCM opens the inspiration
valve based on a certain DA value. The ventilator flow sensor, inspiratory flow sensor, expiratory
flow sensor, and anesthesia machine calibration device collect the flow value of the circuit. The
calibration device sends the collected flow value to the VCM. The VCM uses the flow measured
by the calibration device and the AD values collected by the flow sensors as the data of one
calibration point for flow sensors, and VCM also uses the flow measured by the calibration device
and DA value of the inspiration valve as the data of one calibration point for the inspiration valve.
The VCM controls the inspiration valve to change the DA value to obtain calibration data under a
series of flows, forming a flow calibration data table. The flow should be in the range from 0
L/min to 120 L/min when the inspiration valve is opened during flow calibration.
FIGURE 2 Schematic Diagram of Flow Calibration (Service)