Level - Series LD | Tecfluid

Level Switch Tecfluid LD

The Tecfluid LD series is a point level switch based on vibrating fork technology, suitable for both liquids and granular solids. Operation relies on the change in the fork’s resonant frequency upon contact with process media; this frequency shift is detected by the electronics and converted into a discrete level output.

Main Variants

• LD61: Level detection for liquids
• LD60: Level detection for solids
• LD6XN: NAMUR Ex ia output for intrinsically safe circuits
• LD6XR: Relay output version
• LD6XML: Extended detection length

Technical Selection Data

• Liquid viscosity: up to 10,000 cSt
• Minimum liquid density: >0.6 kg/l
• Switching time: approx. 1 s
• Hysteresis: ±2 mm with water
• Nominal pressure: PN25, depending on process temperature
• Wetted materials: EN 1.4404 / AISI 316L, optional HALAR coating
• Connections: G1 ISO 228-1, 1” NPT, EN 1092-1 DN40 PN25 flange, or sanitary connections ISO 2852, SMS 1145, DIN 11851, TRI-CLAMP

Outputs and Electrical Options

Standard models operate on 24–250 VAC (2-wire) or 12–55 VDC (3-wire), with thyristor output for AC or PNP transistor for DC. Relay version provides DPDT contacts up to 3 A, 250 VAC or 220 VDC. NAMUR version operates at 8–14 VDC per IEC 60947-5-6 / EN 50227.

Applications

Used in tanks under atmospheric or positive pressure, agitated vessels, dosing tanks, distillation columns, evaporators, and for liquid presence detection in pipelines. For pipe detection, vertical installation with upward flow is recommended, minimum diameter DN50, with fork aligned to flow axis.

Certifications

LD6XN series available with ATEX Ex ia IIC T4 or T6, category II 1GD, LOM 10ATEX2007 X certificate.

FAQ

Is this a continuous level measurement?
No. It provides a discrete switching point.

Are there moving parts?
No, detection is achieved via vibration.

What should be considered during installation?
The fork must drain quickly, should not be installed at the filling point, and must be protected in applications with strong agitation.