Float Level Transmitter

How Float Level Transmitters Work

Float level transmitters convert the simple buoyancy principle into a continuous, highly repeatable electronic signal. In the AMETEK LMS TR420 reed-chain transmitter, a precision-balanced float rides on the liquid surface.
Inside the sealed stainless-steel stem, a series of magnetic reed switches and precision resistors form a resistive “daisy-chain.” As the float rises or falls, its internal magnet progressively closes the reed switches, changing the total resistance of the chain.
An integral transmitter circuit conditions that resistance into a linear 4-20 mA or 0-10 V DC output—ready for any PLC, DCS, or SCADA system. Because the sensing elements are isolated from the process fluid and contain no moving parts beyond the float, the TR420 delivers maintenance-free, drift-free level measurement even at 800 °F (427 °C) and 2000 psig (138 bar).

Typical Industries & Applications

• Oil & Gas: separator level control, flare KO drums, chemical injection skids
• Power Generation: condensate and feed-water tanks, turbine lube-oil reservoirs
• Chemical & Petrochemical: reactor vessels, storage terminals, interface detection
• Water & Wastewater: lift-station wells, clarifier basins, sludge hoppers
• Food & Beverage / Pharma: CIP/SIP tanks, breweries, WFI systems (polished 316 L)

Deploying a float transmitter in critical vessels can cut downtime by up to 25% versus sight-glass or switch-only solutions, while providing the continuous data needed for modern predictive-maintenance programs.

Why Choose AMETEK LMS for Float Level Transmitters

Exact-Fit Engineering – Our instrument specialists size every transmitter for your specific temperature, pressure, SG, and material requirements—no guesswork, no overspend.

• Lifetime Reliability – Welded, leak-tested stems and hermetically sealed reed chains routinely achieve >15-year MTBF in refinery, power, and chemical service.
• Seamless System Integration – Native 4-20 mA, HART, Fieldbus, or Modbus outputs eliminate signal converters and simplify commissioning.
• Global Compliance – Full suite of FM, CSA, ATEX/IECEx, CRN, PED, NACE, and SIL documentation speeds project approvals.
• Partner-Level Support – From 3-D modeling for nozzle fits to start-up assistance and spare-parts programs, AMETEK LMS stays engaged for the life of your plant.