Magnetic Level Indicators - Knowledge Base and Selection Guide

Magnetic Level Indicators
Courtesy Orion Instruments

Industrial process control frequently involves the storage of liquid in vessels or tanks. Continuous and accurate indication of liquid level within the tank is an essential data point for safety and process management. While there are a number of methods and instrument types utilized to provide tank level measurement, the instrument of choice is often a magnetic level indicator, also referred to as a magnetic level gauge. Its use for providing level indication has a number of positive attributes:

• Construction that is resistant to breakage.

• Measuring indicators, switches, and transmitters mounted externally, without contacting the medium being measured.

• Maintenance free operation. No regular cleaning needed.

• Readable level indication from greater distance than glass sight gauges.

• Magnetic level indicators can accommodate greater fluid level ranges without the need for multiple instruments.

Orion Instruments, a Magnetrol company and industry leader, has produced a comprehensive guide to magnetic level gauges, switches, transmitters, and related products. It delivers experts and newcomers an understandable and clear description of the technology and principals of operation behind magnetic level gauges and instruments. The guide also assists the reader in properly specifying and selecting the best instrument configuration for an application. A table of contents at the front of the document helps readers to quickly find the information they need.

Take a couple minutes to roll through the document and you are likely to find new and useful application tips and product information. Any questions about magnetic level indicators or your process measurement and control applications can be clearly addressed by a product specialist.

Orion instruments magnetic level gauge & instrument selection guide from Miller Energy, Inc.

Guided Wave Radar for Hygienic Applications: Advantages Over Other Technologies

Guided Wave Radar
for Hygienic
Applications

Operating Principle

Guided wave radar is based upon the principle of TDR (time domain reflectometry). Pulses of electromagnetic energy travel via the waveguide. The pulse is reflected when it contacts a liquid surface and the distance is then calculated.

Guided wave radar transmitters are available with a 304 stainless steel housings designed specifically for use in hygienic applications. This instrument meets the needs and requirements for the wetted and non-wetted materials, process connections and surface finishes of hygienic industries.
Features

• Low dielectric measurement capability (εr >_ 1.4)
• Volumetric output
• Quick connect/disconnect probe coupling
• Operates in visible vapors and ignores most foams
• IS, XP, and Non-Incendive approvals
• Ignores coating buildup

Advantage Over Other Technologies

• Advantage over Differential / Hydrostatic Pressure Transmitter:  Replaced by Eclipse due to setpoint shifts, blockage, leakage, installation cost & long term calibration / maintenance

• Advantage over Magnetostrictive: Replaced by Eclipse due to setpoint shifts, turn-down and clean ability & long term calibration / maintenance.

• Advantage over RF Capacitance: Replaced by Eclipse due to dielectric shifts, coating issues & long term calibration / maintenance.

• Advantage over Load Cells: Eclipse is more cost effective and long term cost of ownership is lower due to long term calibration / maintenance.

• Advantage over Ultrasonic: Replaced by Eclipse due to vapors, condensation, temperature restrictions, foaming & turbulence.

• Advantage over Through Air Radar: Replaced by Eclipse due to performance issues on low dielectric media, short range measurement because of dead band issues in small vessels, measurement issues when using false echo rejection from internal obstructions such as agitators and spray balls, signal attenuation from turbulence, foam, condensation and spray from spray balls used during cleaning or product filling. Through air radar can have issues from variable false echoes generated when spray hits the antenna when vessel is filled from spray balls.

For more information see this Guided Wave Radar bulletin:

Guided Wave Radar Level Transmitter For Hygienic Applications from Miller Energy, Inc.