Ultrasonic Heat Meters

Ultrasonic meters use ultrasonic waves to measure the flow rate of fluid in a pipe. Devices that utilize the Doppler principle emit ultrasonic waves with a constant frequency into the fluid and receive waves reflected from solid particles or bubbles dispersed in the fluid. Due to the movement of particles or bubbles with the fluid, the frequency of the received ultrasonic waves differs from the frequency of the emitted wave. The frequency difference is then proportional to the fluid flow rate.

Advantages: no moving parts, lower pressure losses, the fluid can be aggressive, explosive

Disadvantages: potential errors depending on temperature, density, viscosity, particle concentration