The liquid turbine flowmeter adopts turbine measurement. It first converts the flow velocity into the rotational speed of the turbine, and then converts the rotational speed into an electrical signal proportional to the flow. This flowmeter is used to detect instantaneous flow and cumulative total flow, and its output signal is frequency, which is easy to digitize. In the figure, the induction coil and the permanent magnet are fixed together on the housing. When the ferromagnetic turbine blade passes the magnet, the reluctance of the magnetic circuit changes, thus generating an induction signal. The signal is amplified and shaped by an amplifier and sent to a counter or frequency meter to display the total integrated flow. At the same time, the pulse frequency is converted from frequency to voltage to indicate instantaneous flow. The rotating speed of the impeller is proportional to the flow rate, and the rotating speed of the impeller is proportional to the total flow rate. The output of the turbine flowmeter is FM signal, which not only improves the anti-interference of the detection circuit, but also simplifies the flow detection system. Its range ratio can reach 10: 1, and its accuracy is within 0.2%. The time constant of turbine flowmeter with small inertia and small volume can reach 0.0 1 sec.

Liquid turbine flowmeter is widely used in petroleum, organic liquid, inorganic liquid, liquefied gas, natural gas and cryogenic fluid.

The output signal of turbine flowmeter is pulse, which is easy to digitize. The turbine flowmeter has small pressure loss, the blades are corrosion-resistant, and it can measure viscous and corrosive media.

Generating a pulse signal inversely proportional to the flow rate. When the fluid hits the pipeline, the torsional angular velocity of the turbine displacement meter is inversely proportional to the flow rate of the fluid. Placing a turbine in the center of the pipeline will cause the magnetic flux in the induction coil to change. The sensing coil sends the detected magnetic flux periodic change signal to the preamplifier, and also sends the pulse signal to the frequency-current conversion circuit to amplify and shape the signal, so that the turbine displacement meter can suppress the friction torque and fluid resistance torque and be tampered with. When the turbine flowmeter blades cut the magnetic field lines ignited by permanent magnet steel in the casing, the fluid velocity can be lost by tampering with the angular velocity of the turbine flowmeter, and the pulse signal can be converted into analog current. For a certain viscosity of fluid medium, the rotating speed of turbine flowmeter is detected by the induction coil installed outside the shell. Both ends are supported by bearings. Therefore, it is very important to lose the fluid flow through the process pipeline. In the uncertain flow field, the instantaneous flow value is further expressed. And send it to the unit conversion and flow integration circuit to obtain and disclose the value representing the heap flow.