Ultrasonic Level Transmitters

Babbitt ABM Series Ultrasonic Level Transmitters allow simple and reliable non-contact level measurement of fluids in plastic, metal or concrete tanks, sumps or other containers. The microprocessor-controlled circuit generates a pulse that sends a sound wave from the transducer face down to the fluid level which is then reflected back. The transit time is measured and converted into a 4/20mA signal. Because the speed of sound changes with air temperature, each transducer has a built-in temperature sensor which compensates for air temperature inside the tank.

Babbitt ABM Series Ultrasonic units have a proprietary circuit that locks onto the echo farthest from the transducer face which will always be the fluid level. This circuitry automatically filters out false echoes that may be produced by peripheral obstructions inside tank. Each unit also features a self-cleaning face which eliminates condensation. All Babbitt ABM Series offer simple, single push-button calibration. These units can be calibrated either inside the vessel, on the bench or with the factory provided software. For a brief demonstration of this simple calibration, see the short video below.

Babbitt offers Ultrasonic non-contact, continuous level sensors with measuring ranges from 5” up to 90’ with features to meet a variety of industries. Units are available in 4 wire (115VAC), 3 wire (24VDC) and 2 Wire Loop Power with HART 7 communication. Digital displays with optional set points for self-contained alarm and control systems are available from the factory. High temperature, high pressure and sanitary models with tri-clamp connections are also available. (See ordering information below) Proper installation and mounting is critical for consistent and reliable operations. (See Installation and Mounting PDF below) For general questions regarding ultrasonic units or unsure of whether an ultrasonic is right for your application, please see our FAQ page.

Product Features:

  • Simple push button calibration
  • Self-cleaning face eliminates condensation
  • 4-20mA or 20-4mA output
  • Non-volatile memory-batteries not required
  • Microprocessor based reliability
  • Ignores peripheral obstructions
  • Built-in temperature compensation
  • Field, bench or software calibration


  • Water/Wastewater
  • Food/Beverage
  • Chemicals/Oils
  • Viscous Fluids/Slurries
  • Pharmaceutical


  • Water without foam
  • Liquids without methane, CO2 and H2S
  • Water and solid mixtures
  • Oil without H2S
  • Inks and water based paint containers (low fume)
  • Sanitary applications with CIP



Power: 115VAC/60Hz, 230VAC/50Hz, 12-30VDC or 2 Wire Loop Power
Output: 4/20mA or 20/4mA, 6.1uA resolution 750 ohms, isolated w/ AC supply; non-isolated w/ DC supply
Fuse: 0.125A/250V type 2AG


Process Entry: Threaded per chart
Conduit Entry: ½”NPT – plastic conduit
Transducer: PVC Standard; Teflon Optional
Enclosure: PVC-94VO Standard; Aluminum and Stainless Steel Optional


Temperature: Standard PVC (-40 F to 140 F); Optional High Temp with Teflon Transducer (-40 F to 266 F)
Pressure: Standard Models (15 PSI Max.); Optional HTP Sanitary or special High Pressure sensor (72 PSI)
Approvals: General Approvals CSA and FM; must have Aluminum enclosure


Dead Zone/Range: Depends on model, see chart
Accuracy: +/- 0.25% of span
Lost echo hold time: 30 seconds/output 22mA or 2mA – User programmable

Specifications subject to change without notice

Model NumberOperating RangeOperating FrequencyMounting Thread
ABM200/300/400-25U 17” to 90’ 25Khz 6” NPT
ABM200/300/400-45U 12” to 60’ 45Khz 3” NPT
ABM200/300/400-52U 11” to 50’ 52Khz 3”/2” NPT
ABM200/300/400-70U 10” to 30’ 70Khz 2” NPT
ABM200/300/400-80U 8.5” to 20’ 80Khz 2” NPT
ABM200/300/400-81U 7” to 16’ 81Khz 1.5 NPT
ABM200/300/400-148U 5” to 9’ 148Khz 1” NPT

ABM Series Ultrasonic Level Transmitter

ultrasonic level transmitter

Software Downloads

Communication Software for 3 and 4 Wire Radar and Ultrasonic (rev. 7.2) → Download Here

Communication Software with HART7 (rev. 2.8) → Download Here