What is the function of velocity meters in fluid measurement?

Velocity meters are specifically designed to assess the flow rate of a fluid by measuring a property that correlates directly with the fluid's velocity. These meters operate on the principle that the rate of flow is dependent on how fast the fluid is moving through a pipe or conduit.

By measuring velocity, typically using mechanisms such as Doppler effect, magnetic fields, or ultrasonic signals, the meter can inform the user about the flow rate when combined with the cross-sectional area of the pipe. This information is critical in various industrial applications where knowing the flow rate of liquids and gases is essential for process control and efficiency.

In contrast, pressure meters gauge the force being exerted by the fluid, temperature sensors assess the thermal state of the fluid, and density meters determine how compact the substance is. Each of these devices serves a distinct function unrelated to directly measuring flow rate based on fluid velocity.