Patent ID: 11857775
Assignee: HONEYWELL INTERNATIONAL INC.
Field: Measurement (Instruments)
Classification: CPC A  G | IPC A  G

Claim 0:
1. A method for detecting an air bubble or liquid in a flow tube of a fluid flow system, the method comprising:
monitoring a first output signal of a force sensor of the fluid flow system for a change from the first output signal to a second output signal, wherein the change from the first output signal to the second output signal comprises at least one of a change in amplitude of an Alternating Current (AC) component of the first output signal and a change in a signal level of a Direct Current (DC) component of the first output signal;
detecting the change from the first output signal to the second output signal, wherein the change in the amplitude of the AC component is detected based on an increase or a decrease of the amplitude of the AC component, and the change in the signal level of the DC component is detected based on a shift of the signal level from a first signal level to a second signal level;
determining one of a time duration of the second output signal of the force sensor from an instance the first output signal is changed to the second output signal, and a number of transitions in consecutive signal levels of the DC component from the first signal level to the second signal level;
comparing the time duration of the second output signal with a predefined time and the number of transitions with a predefined number of transitions; and
determining a threshold when one of the time duration of the second output signal exceeds the predefined time, and the number of transitions of the DC component exceeds a predefined number of transitions, wherein the threshold is determined based on a predefined percentage of the second output signal.