LC and LE Series Float Level Switches Transmitters

The Tecfluid LC and LE series are robust float-operated level devices for point detection (LC) and continuous measurement (LE) of liquids in tanks, with top or side mounting via external chambers.

• Series LC (Float Level Switch): Point level switch with accuracy ±2 mm. Models LCM (<2000 mm guide tube, up to 3 reed switches, density ≥0.7 kg/l) and LC (>2000 mm or >3 switches, density ≥0.6 kg/l). Materials: AISI 316L, PVC, PP, PVDF, PTFE.

• Series LE (Float Level Transmitter): Continuous level transmitter with 10 mm resolution. Models LEM (<2000 mm, density ≥0.7 kg/l) and LE (>2000 mm, density ≥0.6 kg/l). 4–20 mA output (optional HART, PROFIBUS, Modbus) and optional local level indication + alarms.

Both series provide hermetic installation, high chemical compatibility, and are suitable for hazardous areas (ATEX).

Operating Principle

A magnetic float moves along a guide tube following the liquid level. Inside the tube are reed switches (LC) or a chain of reed switches/resistors (LE).

• In LC, the float’s magnet activates bistable (RBC) or monostable (RSC) reed contacts at preset points, generating discrete on/off signals.

• In LE, the float progressively activates reed switches connected to a resistor chain, producing a variable resistance that is converted into a 4–20 mA analog signal proportional to level. One float can operate multiple independent switching points (minimum distance 70 mm). The principle is independent of conductivity and works with viscosities up to 1500 cSt.

General Technical Specifications

Compact polycarbonate/aluminium housing, protection IP65–IP68, vertical top or side mounting. Measuring range: 150–6000 mm (guide tube up to 6 m). Materials: guide tube & flanges — AISI 316L, PVC, PP, PVDF, PTFE; float — matching materials. Process temperature: –20…+150 °C (AISI 316L/PTFE/PVDF), 0…+50 °C (PVC), –10…+80 °C (PP). Pressure rating: PN16 (AISI 316L), PN10 (plastics). Hysteresis: ±4 mm (LC), ±5 mm (LE); accuracy ±2 mm (LC), resolution 10 mm (LE). Outputs: LC — 1–6 reed switches (1 A/220 V, 60 VA, RBC/RSC); LE — 4–20 mA (TR3420 Ex d, TR2420 Ex ia), optional HART/PROFIBUS. Certifications: ATEX (Ex ia/Ex d), “Simple Apparatus” for LC. Process connections: DN50–DN100 flanges (EN 1092-1/ASME B16.5), G1½"/1½" NPT threads.

Main Application Areas

• Industrial process control and dosing

• Food & beverage storage tanks

• Shipbuilding and marine (fuel, ballast, service tanks)

• Chemical and textile industries (aggressive/corrosive liquids, hazardous areas)

• Pump protection (start/stop, high/low alarms, overfill prevention)

Advantages of LC/LE Float Level Devices

• Simple, reliable design with no moving parts inside the tube → minimal maintenance

• Excellent chemical resistance (wide choice of plastics and stainless steel)

• Fully hermetic and safe for aggressive or hazardous environments (ATEX certified)

• High accuracy (±2 mm) and flexibility (up to 6 independent points, lengths to 6 m)

• Versatile mounting (top/side, flange/thread) and low-density capability (≥0.6 kg/l)

• Immune to foam, turbulence, and condensation

• Low total cost of ownership

• LE series offers continuous 4–20 mA measurement with fieldbus integration for advanced control systems