The ultrasonic phase shift flowmeter is an instrument that calculates the flow velocity and flow rate of a fluid by detecting the phase difference of ultrasonic signals when they propagate in the downstream and upstream directions.

1. Extremely high resolution and low flow velocity sensitivity: This is its most prominent advantage. Due to the amplification effect of high frequency (MHz), it is highly sensitive to minute changes in flow velocity and can measure extremely low flow velocities (down to the order of 0.001 m/s), with a very low lower limit of measurement range.
2. High theoretical accuracy: The phase measurement technology is highly mature and can achieve very high accuracy.
3. Strong anti-interference ability: Phase information is less affected by signal amplitude attenuation, and it is more tolerant of bubbles and particles than the amplitude-dependent beam deflection method, but not as robust as the time difference method.
4. Relatively straightforward signal processing.

1. Blood flow measurement: In medical equipment, it measures the blood flow velocity in human blood vessels or extracorporeal circulation pipelines.
2. Micro-flow measurement and laboratory research: Microfluidic chips, chemical reactors, and small-flow calibration devices in laboratories.
3. High-precision water flow standard device: As a transfer standard or comparison standard, it provides high-precision calibration for other flowmeters in the low-flow range.
4. Special industrial processes: Precise control and measurement of small flows of lubricating oil, hydraulic oil, and expensive chemical reagents.

The ultrasonic phase shift flowmeter is a model of the pursuit of "ultimate resolution" and "low flow rate detection capability" in ultrasonic flow measurement technology. It ingeniously converts the "time difference - phase difference" to amplify the hard-to-capture tiny time signals into phase signals that are easy to measure precisely.