The pressure range selection is large, and the small field pressure cannot be collected.
The pressure calibration parameters in the instrument have been restored to the factory settings (if the factory is restored, the voltage value in the P21-P25 screen will be 0.0) and need to be re-implanted.
The D2 model is slow in collecting pressure, and the pressure does not refresh when the flow is not going, press SET to turn the parameters over from the beginning.
In the case of an inaccurate pressure display for a long time, it needs to be returned to the factory for recalibration.
If the pressure keeps showing a constant pressure, ask for the pressure value and check whether the value is the upper limit of the pressure change, if it is, the pressure change will be small.
Solution:
Temporarily adjust the fixed pressure compensation.
Return to the factory to replace the pressure change or calibrate the pressure change.