Talk about the understanding of dual-channel ultrasonic flowmeter

　　QTLS series dual-channel ultrasonic flowmeters can be divided into propagation velocity difference method, Doppler method, beam shift method, noise method and correlation method according to the signal detection method. The Doppler method uses the acoustic Doppler principle to determine the fluid flow rate by measuring the ultrasonic Doppler frequency shift scattered by scatterers in the inhomogeneous fluid. It is suitable for measuring the flow rate of fluids containing suspended particles, bubbles, etc. The beam shift method uses the propagation direction of the ultrasonic beam in the fluid to produce a shift as the fluid flow rate changes to reflect the fluid flow rate. At low flow rates, the sensitivity is very low and the applicability is not great.

　　The "time difference method" measurement principle is widely used at present. Combined with multi-pulse technology, digital information processing technology and signal processing circuit, the measurement data is displayed in real time. The "time difference method" is to generate an ultrasonic signal through the sending sensor and radiate it in the air flow. The signal passes through the pipe wall and fluid to the receiving sensor. At the same time, the receiving sensor radiates the same ultrasonic signal, and the signal passes through the pipe wall and fluid to the sending sensor. At this time, because of the existence of flow velocity, the time difference can be used to calculate the flow velocity and then the flow rate.

　　1. Supports both mono and dual channels, and when one channel is abnormal or disconnected, it can automatically switch to mono operation according to the signal quality;

　　2. Using the latest 32-bit Cortex-M4 core CPU as the processor core, using 64-bit floating-point operations, the calculation does not lose precision;

　　3. High-speed ADC is used to collect ultrasonic signals, and it has ultrasonic waveform restoration and reconstruction technology; precision time measurement chip is used, and the accuracy of ultrasonic flight time can reach 22 picoseconds;

　　4. Single board, full patch process, all using SMT machine welding, greatly reducing the circuit board cold soldering, leaking soldering, short circuit and other problems.

　　5. Heat function: Optional PT100 external clamp-on platinum resistor can realize heat measurement.

　　The above is what the ultrasonic flowmeter manufacturer has to say about the understanding of dual-channel ultrasonic flowmeters. You can make some references based on the above content. I hope it can help users understand more maintenance methods during use and reduce measurement errors during the use of the instrument. Regular maintenance and maintenance of the instrument can effectively improve the performance of the instrument.