How Electromagnetic Flowmeters Work

Electromagnetic flowmeters, also known as magnetic flowmeters or magmeters, use Faraday’s Law of Electromagnetic Induction to determine the flow of liquid in a pipe. In an electromagnetic flowmeter, a magnetic field is generated and channeled into the liquid flowing through the pipe. Following Faraday’s Law, flow of a conductive liquid through the magnetic field will cause a voltage signal to be sensed by electrodes located on the flow tube walls. When the fluid moves faster, more voltage is generated. Faraday’s Law states that the voltage generated is proportional to the movement of the flowing liquid. The electronic transmitter processes the voltage signal to determine liquid flow.

In contrast with many other flowmeter technologies, electromagnetic flowmeter technology produces signals that are linear with flow. As such, the turndown associated with magnetic flowmeters can approach 20:1 or better without sacrificing accuracy. Continue reading “How Electromagnetic Flowmeters Work”

How Ultrasonic Flowmeters Work

animation of flow moving through ultrasonic flowmeter

animation of flow moving through ultrasonic flowmeterUltrasonic 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 Doppler effect. When the fluid moves faster, the frequency shift increases linearly. The transmitter processes signals from the transmitted wave and its reflections to determine the flow rate. Continue reading “How Ultrasonic Flowmeters Work”

How Paddlewheel Flowmeters Work

Paddlewheel flowmeters use the mechanical energy of the fluid to rotate a paddlewheel (just like a riverboat) in the flow stream. Paddles on the rotor are inserted into the flow to transform energy from the flow stream into rotational energy. The rotor shaft spins on bearings. When the fluid moves faster, the paddlewheel spins proportionally faster. Shaft rotation can be sensed mechanically or by detecting the movement of the paddles.

Paddle movement is often detected magnetically, with each paddle or embedded piece of metal generating a pulse. When the fluid moves faster, more pulses are generated. The transmitter processes the pulse signal to determine the flow of the fluid. Continue reading “How Paddlewheel Flowmeters Work”

Monitoring Solutions for Semiconductor Subfabs

A semiconductor transistor is a part with specific electronic properties that allow it to serve as a component in microchips and modern electronics like phones, laptops, and more. As these components are small and require precise manufacturing methods, there are facilities dedicated to their manufacture. 

These facilities consist of several levels including air handlers and scrubbers for exhaust, HEPA room, fab cleanroom, and subfab areas. The control of pressure, flow, and temperature within the facility is essential. 

Semiconductor subfabs are located directly below the cleanroom. Here you will find an array of ancillary equipment, such as vacuum pumps, abatement systems, chillers, gas cabinets, and other equipment to keep process tools functioning efficiently. The equipment within the subfab is interconnected with the tools found within the fab cleanroom itself; these separate but connected areas work together to make sure the facility runs smoothly.  Continue reading “Monitoring Solutions for Semiconductor Subfabs”