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Flow Measurement with Orifice Plates

Dwyer Instruments offers many types of flow measuring products including orifice plates, which are used as a flow sensing element with a differential pressure monitor.

Orifice Plates

Orifice plates are a primary flow element, detecting the flow of a fluid passing through the plate by sensing the pressure drop across the plate. When a fluid flows through a restriction in a pipe, it creates a pressure difference between upstream and downstream of the restriction. This pressure difference is proportional to flow rate according to Bernoulli’s principal, similar to a Pitot tube.  Orifice plates are commonly used as they are simple to use, low cost, work with gases or liquids, and require low maintenance.  Adversely, they do have large pressure losses with about 50% of the pressure drop not recoverable.  Continue reading “Flow Measurement with Orifice Plates”

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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”

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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”

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Semiconductor Tool Parameter Monitoring Solutions

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 process tools are used for the production of microchips and other microelectronic components. These process tools are highly engineered and have a multitude of applications such as pneumatics, electrical, electronics, fume exhaust, chemical & gas distribution, radio frequency (RF) generation, and ultra-high vacuum. Dwyer products help to ensure that process tools are being monitored and controlled to the system owner’s designated parameters.  Continue reading “Semiconductor Tool Parameter Monitoring Solutions”

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Monitoring Solutions for Semiconductor HEPA/ULPA Rooms

Semiconductor Fab with HEPA/ULPA Room Highlighted

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 differential pressure within the facility is essential for the safety of both equipment and personnel.

Semiconductor Fab with HEPA/ULPA Room Highlighted
Semiconductor Fab HEPA/ULPA Room

The HEPA/ULPA rooms are found in the space above a semiconductor cleanroom. This area has filtration equipment that removes particulates from the outside environment. A HEPA (high efficiency particulate air) filter and/or an ULPA (ultra low particulate air) filter is used to trap small contaminants and prevent them from entering the fab cleanroom area. The fab cleanroom has to be free of particulates, as it is where semiconductor devices such as microscopic transistors are manufactured. Something as small as a molecule from a fragrance can destroy one of these transistors, making proper filtration an essential part of the semiconductor fabrication process.  Continue reading “Monitoring Solutions for Semiconductor HEPA/ULPA Rooms”