When we talk about digital flow meter for hydraulic oil, we often refer to digital turbine flowmeter, oval gear flow meter and Coriolis flow meter.
A turbine flow meter is a kind of digital oil flow meter used to generate electric signals using turbines. It consist of turbines which when the fluid passes through them rotate at an angular velocity depending on the rate of flow of the fluid. This angular velocity of turbines engages the rotor causing it also to have an angular velocity. The angular velocity depends on the radius of the turbines in the rotor. classically the rotor is the only part that has the movements in the flow meter.
The angular velocity that is caused by the rotating turbines make the rotor to generate electric signals which are majorly alternating current. The frequency of the electric signals is directly proportional to the rate of liquid flow.
Oval gear flow meter is digital oil flow meter where positive displacement-type volume meters are used to transport defined volumes into the measuring chambers. It contains two toothed oval gears that are usually driven by the medium flow causing them to mesh among themselves. The rotation of the two oval gears depends on the amount of fluid that will be passing through the meter. therefore, the rotation of the two oval gear is directly proportional to the amount of the volume passing past the meter. Oval gear flow sensor can be mechanical type, but can also develop into digital flow meter with flow transmitter.
The oval gears flow transmitters are designed to produce the best performance with minimum cost of production.
This is a digital oil flow meter that artificially causes Coriolis acceleration within the flowing stream and by detecting the angular momentum gained, it measures the mass flow. Rotating a pipe containing flowing liquid at a point, inertia force is generated by the fluid and is always at a right angle with the flow direction.
Fluid flowing in a pipe is usually subjected to Coriolis acceleration which causes rotation of the pipes.