How Positive Displacement Flowmeters Work Positive displacement flowmeter technology is the only flow measurement technology that directly measures the volume of the fluid passing through the flowmeter. Positive displacement flowmeters achieve this by repeatedly entrapping fluid in order to measure its flow. This process can be thought of as rep

How Differential Pressure Flowmeters Work Differential pressure flowmeters use Bernoulli''s equation to measure the flow of fluid in a pipe. Differential pressure flowmeters introduce a constriction in the pipe that creates a pressure drop across the flowmeter. When the flow increases, more pressure drop is created. Impulse piping route the upstre

How Ultrasonic Flowmeters Work Ultrasonic flowmeters use sound waves to determine the velocity of a fluid flowing in a pipe. At no flow conditions, the frequencies of an ultrasonic wave transmitted into a pipe and its reflections from the fluid are the same. Under flowing conditions, the frequency of the reflected wave is different due to the Do

How Lubrication Vane Style Flowmeters Work Variable area flowmeters measure flow by allowing the flow stream to change the opening within the flowmeter by moving an internal part. When the flow increases, the fluid generates more force and moves the internal part farther. Vane-style variable area flowmeters have a spring-opposed vane that mov

How Water Vortex Shedding Flowmeters Work When a fluid passes by an object or obstruction, oscillations can occur. Examples of these oscillations in nature include the whistling caused by wind blowing by the branches of trees, the swirls produced downstream of a rock in a rapidly flowing river, and the waving of a flag in the wind. Note that in