Magnetic Liquid Level Gauges in Industrial Settings

Magnetic liquid level gauge combined with
guided wave radar in a single assembly
Vega Americas

Magnetic liquid level gauges are an excellent alternative to sight glass level gauges for many process measurement applications. Their reliable performance and adaptability to process requirements has made them a primary choice in the industrial arena.

Essentially, a magnetic level gauge or magnetic level indicator, is a sight glass with enhancements that provide better readability and a form factor enabling the inclusion of additional level monitoring functions on the same device. Where a sight glass requires operator proximity to read liquid level, the magnetic level gauge's indicating scale, or flags, can be clearly viewed from a considerable distance. A sight glass gauge can also be hindered by difficulties in visually determining liquid level because of deterioration of the glass surface or physical properties of the liquid. Magnetic level gauges remove the need to observe the liquid directly by incorporating a float device within a tube connected to the liquid containing vessel. As the float moves in response to liquid level changes, its magnet causes the indicator flags on the scale to rotate and display either a black face, indicating no liquid present at that position, or a colored face.

Magnetic level indicators or gauges can be modified with a range of options, including armored casings to protect the tube and float arrangement and limit switches to signal attainment of predetermined liquid levels. Combining a magnetic level indicator with another level measurement technology, such as guided wave radar or magnetostrictive, in a single assembly can provide an analog process signal representing continuous liquid level and serve as a redundant measuring device for critical applications.

The document included below provides illustrated detail about the devices and their proper application. There is more detail available, so share your process measurement requirements and challenges with instrumentation experts. The combination of your process knowledge and their product application expertise will produce effective solutions.

Combination magnetic and guided wave radar liquid level indicator from Classic Controls, Inc.

Selecting the Right Flow Meter Technology

Vortex Flow Meter
Courtesy Yokogawa Corp.

Magnetic Flow Meter
Courtesy Yokogawa Corp.

Many industrial process control operations require fluid flow measurement as an essential element in the process design. Accurate flow measurement can be obtained with the proper application and installation of a flow meter as part of the fluid transfer system.

Industrial flow meters employ differing technologies to directly or indirectly measure fluid flow rates. Among the many available technologies for fluid flow measurement, vortex flow meters, magnetic flow meters, Coriolis flow meters, and rotameter flow meters are among some of the most common found in industry.

Coriolis Flow Meter
Courtesy Yokogawa Corp.

Rotameter Flow Meters
Courtesy Yokogawa Corp.

Each of the separate technologies have attributes which can make them more suitable to certain applications. Selecting the most appropriate flow measurement technology for an application is one of the initial and crucial steps to designing a well functioning fluid measurement system.

Selection criteria, such as fluid temperature, pressure, and velocity will be part of the selection process. Additional considerations include whether the fluid may be abrasive, corrosive, clean or dirty. The state of the fluid, liquid or gas, must also be considered.

The table below provides quick general guidance on which technologies to consider, based upon the factors outlined above. This will help you better focus further product selection research efforts.

Flow Meter Technology Selection Table
Courtesy Yokogawa Corporation of America

Selecting the right device is not always an easy task, especially since it may be something that you do infrequently. Manufacturers often have knowledgeable local representatives that are experienced in this field and more than willing to contribute their expertise to your selection process.