Liquid Level Indicator

Magnetic liquid level sensors pick up the slack where sight glasses fall short

Magnetic sensors have emerged as the preferred sensor for applications where visual communication of liquid levels is crucial. Traditional sensors consist of a float located inside a solid housing that communicates with an external indicator. Simple in design, it is not foolproof and plants are seeing its downfalls in certain applications. Colorless liquids are very difficult to see and breakable glass poses as a potential hazard if it cracks and spills hazardous materials.

Magnetic liquid gauges offer simple visual indication coupled with a transmitter that can deliver readouts from remote locations. As liquid levels rise the magnet-equipped float moves within the float chamber, and small magnets embedded in the flags rotate 180 deg to show its opposite side and color as it passes by. Magnetic sensors perform in high temperature, high pressure, and high vibration environment and many other applications requiring sturdy, high-quality design.

Best-in-Class Liquid Level Indicators feature:

• Continuous-level digital transmitter for control or remote indication
• Dependability in harsh environments and capabilities of high pressure and temperatures of at least 4200 PSIG and 750 degrees F
• Add on switch capabilities for alarms and level controls

Top Considerations before Buying Liquid Level Indicators:

For simple operation with long-lived accuracy ensure that the inside of the magnetic level indicator is transparent and hermetically-sealed. The indicator magnetically should float up and down inside the indicator tube with the rising and falling of liquid levels. Brightly colored indicators will allow the operator to read the level from 100 feet away. Consider only those designs that are capable of working within the required materials of construction that can function at the required accuracy and operating temperature.

Key Providers:

1. John C. Ernst Company Inc., founded in 1969, develops and specializes in process engineering equipment and devices for applications involving water, steam, oils, gases, chemicals, and sanitary projects. The company's produces flowmeter solutions for water, steam, acid, chemicals, air, gases, and high viscosity fluids. In addition to differential pressure flowmeters, other flowmeter devices can are dial type, digital with total and rate displays, shuttle type, variable area, and positive displacement oval gear type for high or varying viscosity fluids. Flow meters are available with 4-20mA transmitters, remote readout, pulse signals, can be field calibrated for fluids other than water, and can be battery operated when input power is not an option. We now have a Digital Flow Meter in PVDF Housing for aggressive chemicals. Additionally, the John C. Ernst Company manufactures and supplies observation equipment such as sight glasses, liquid level gauges, sight flow, illuminators, ejectors, and eductors for the petro-chemical, chemical processing, processing, food & beverage, dairy, pharmaceutical, semi-conductor, and boiler room equipment industries.

2. Automation Products Inc., a private company established in 1960, develops, manufactures and markets the Dynatrol Systems of on-stream process analyzers, measurement and control instruments, level detectors, plus a line of new accessories. Dynatrol viscosity equipment is available for either in-line measurement or as a separate “stand alone” design for applications including liquid paints, primers and fluorescent coatings as well as the properties of other fluid products used in the manufacture of plastics and other polymers. The company's Dynatrol Density Cells are available in a wide variety of corrosion-resistant materials, and are complete when paired with one of our newest Digital or Analog output Converters. The Density Systems are available as well with the Red Goose Pipeline Product Sampling System.

3. Orange Research Inc. specializes in differential pressure technology, manufacturing differential pressure gauges, switches, transmitters, sensors and transducers; flow meters and flow switches; and liquid level switches. Founded in 1968, with work beginning on an indicator to compare differing pressures, the company over the intervening years has produced differential pressure applications for monitoring filtration equipment, compressors and heat exchangers for a wide variety of industries including oil refining, chemicals and semiconductors.

4. Consider Greyline Instruments, Inc. as your provider of ultrasonic level sensors. The Stingray Portable Level-Velocity Logger for area-velocity flow surveys in sewers, streams and open channels is a battery operated data logger that outputs readings with the convenience of compact portability. Using Windows software Stingray tracks level readouts in real-time intervals. Store liquid levels, velocity and water temperature with up to 130,000 data points. Use it for flow surveys, I&I studies, stormwater, irrigation water and sewage.  Greyline Instruments Inc. specializes in ultrasonic level transmitters, pump station controllers, tank farm monitoring systems, software systems and data loggers.

Liquid Level Indicators
Definition: An assembly of lines, tanks, pumps and other devices necessary to control the levels, especially the levels of liquids and gasses, in a process tank. Typical level control systems: float, solid probe, steel rope capacitance, ultrasonic, acoustic, microwave radar, hydrostatic, and differential pressure types. See also level sensors, level switches, level measurement instrumentation.