Magnetic Level Instruments

Magnetic level indicators use the principle of magnetic coupling. A float containing a permanent magnet moves up and down with the liquid level inside a chamber. Outside the chamber, a visual indicator— a column of rotating flags —responds to the float’s magnet, displaying the level accurately without direct contact with the process fluid.​

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• Improved safety: No direct glass exposure to process fluids.​

• Low maintenance: No moving parts in the visual indicator, and float-based systems are durable.​

• High visibility: Indicators are readable from a distance.​

• Sealed system: Ideal for hazardous or pressurized environments.​

• Customizable: Can be equipped with transmitters and switches for remote monitoring or alarms.​​

Yes. Magnetic level instruments are often preferred for high-pressure and high-temperature applications, especially when using materials like stainless steel or exotic alloys. Many instruments are rated for pressures up to ANSI 2500 class and temperatures up to 400°C (752°F) or more, depending on construction and certification.​​

Magnetic level instruments can handle a wide range of fluids, including:​

• Clean liquids​

• Corrosive chemicals (with proper material selection)​

• Viscous or dirty liquids ​

• Cryogenic and boiling liquids​

They are not ideal for solids or very thick slurries that may impede float movement.​​

Absolutely. Most modern Magnetic Level Indicators can be paired with:​

• Reed-chain or guided wave radar transmitters for continuous level output (4–20 mA, HART, etc.)​

• Magnetic switches for high/low level alarms​

• Digital displays or control systems for integration into plant SCADA/DCS networks​​

The Magtech MLT is a magnetostrictive level transmitter that provides continuous, high-accuracy level measurement. It can be mounted externally or directly inserted into the tank or bypass chamber. A transmitter provides a 4-20mA or digital signal for control systems and is paired with a magnetic level indicator that provides the visual local indication at the tank or bypass chamber. 

• No direct glass exposure (safer than sight glasses) ​

• Low maintenance and long service life ​

• Redundant measurement when paired with radar or transmitters ​

• Clear visual indication even in harsh environments ​

• Suitable for high-pressure and high-temperature applications

Yes, MLIs can be combined with guided wave radar, non-contacting radar, or magnetostrictive transmitters like the MLT for redundant or enhanced level measurement. 

The Rosemount 9935 Bypass Chamber is a high-integrity chamber designed to house a float for use with magnetic level indicators and transmitters. It ensures safe, isolated measurement in pressurized or hazardous applications and supports integration with radar or magnetostrictive technologies.

A magnetic level indicator is a device that uses a float and magnetic coupling to provide a visual representation of liquid level without direct contact with the process fluid.

Magnetic level measurement offers:​

• Non-invasive operation​
• Improved safety​
• Low maintenance requirements​
• Reliable performance in harsh environments

Use magnetic level instruments when you need:​

• Safe level indication in high-pressure or corrosive environments​
• A low-maintenance alternative to sight glasses​
• Local visual indication with optional remote monitoring

Yes, magnetic level instruments can be paired with guided wave radar transmitters, non-contacting radar transmitters and switches to provide continuous level monitoring, alarms, and integration into control systems.