Level transmitters are used to provide continuous measurement of liquids inside tanks, vessels or other containers. The media level is detected and converted into a 4/20mA output signal, which can be displayed locally on site or sent to a PLC, DCS or other management system. Level transmitters can be used as standalone instruments or in conjunction with Point Level Switches as part of an Overfill Prevention Management System.
Babbitt offers a variety of continuous level measurement instruments designed to provide reliable monitoring of liquids, including solvents, acids, oils, wastewater and slurries. Although each technology has proven successful, choosing the correct instrument will depend largely on the application and process conditions. Level transmitters is a broad term frequently used to describe a Liquid Level Transmitter, Ultrasonic level Transmitter, Magnetostrictive Level Transmitter and a Radar Level Transmitter, all of which provide continuous level measurement and tank level measurement.
To determine which instrument is the best suited for your application, visit the the Continuous Measurement Product Selection Guide or contact us for application assistance.
Frequently Asked Questions
What is a continuous level transmitter? +
A continuous level transmitter provides ongoing measurement of liquid inside a tank or vessel, rather than a single on/off point. The instrument detects the media level and converts it into a 4/20mA output signal, which can be shown on a local display or sent to a PLC, DCS, or other control system. Continuous transmitters can operate as standalone instruments or alongside point level switches as part of an overfill prevention management system.
What continuous level transmitters does Babbitt offer? +
Babbitt offers two continuous level transmitter product lines:
- LTM Magnetostrictive Level Transmitter - a loop-powered, direct insertion or externally mounted transmitter using magnetostrictive float technology.
- LT9000 Level Transmitter - an RF admittance (capacitance) transmitter for electrically conductive, non-coating liquids.
"Level transmitter" is also used industry-wide to describe ultrasonic and radar technologies, but the LTM and LT9000 are the two continuous measurement instruments Babbitt manufactures.
What's the difference between the LTM Magnetostrictive Transmitter and the LT9000? +
The LTM uses a magnetostrictive wave guide and float assembly. A current pulse travels the wave guide, and the timing of its interaction with the float's magnetic field precisely determines level. It is unaffected by heavy vapors, emulsion layers, condensation, or foam, and can be configured for total level or interface applications.
The LT9000 uses RF admittance technology, measuring the change in capacitance between the probe and vessel wall. It's built for electrically conductive liquids that don't leave a sticky residue or buildup, and is a strong fit for short measuring ranges or vessels with obstructions that would interfere with non-contact sensors.
What output signal do Babbitt transmitters provide? +
Both the LTM and LT9000 provide a standard 4/20mA output signal. The LTM also supports HART and FOUNDATION Fieldbus digital communication (LTM-350S), with "plug-and-play" electronics that allow an upgrade from HART to Fieldbus without replacing the sensor probe. The LT9000's isolated 4-20mA output can drive a load of up to 1,000 ohms.
Are these transmitters rated for hazardous locations? +
Yes. The LTM-250S and LTM-350S feature explosion-proof, dual compartment enclosures and are CSA-US approved for Class I, Div. 1, Groups B, C, D, E, F, G and Class III installations (NEMA 4X, IP66). The LT9000 has an explosion-proof cast aluminum enclosure rated Class I, Groups C and D, and Class II, Groups E, F and G.
Can these transmitters measure interface level, not just total level? +
Yes, for the LTM Magnetostrictive line. It can be configured for liquid level or interface applications, with a dual float configuration available for interface measurement in addition to total level.
How do I know which transmitter is right for my application? +
The right instrument depends on your process conditions, including liquid conductivity, coating tendency, vessel obstructions, required measuring range, temperature and pressure, and area classification. Fill out the LTM or LT9000 data worksheet, or contact Babbitt directly for application assistance.
Will these transmitters integrate with my existing PLC or DCS? +
Yes. The standard 4/20mA output from either transmitter can be wired directly into a PLC, DCS, or other management system, or displayed locally on site. The LTM additionally supports HART and FOUNDATION Fieldbus protocols for systems built around those communication standards.
