Hygienic vibrating fork level switch for liquids

Liquiphant FTL33

11-35 Pcs.


Tri-clamp version - right (stock model has no tube)


  • 3-A and EHEDG certificates
  • Robust stainless steel housing (316L)
  • External function test with test magnet




Vessels or pipes (from DN25)

Product density:

>0.7 g/cm³

(opt. >0.5 g/cm³)

Product temperature:

–40 to +100 °C/+150 °C

Product viscosity:

≤ 10 000 mm2/s (cSt)

Process pressure:

Max. 40 bar

Product/VersionPrice/pcs. in NZ$Order code
Liquiphant FTL33
Power Supply; Output
Electrical Connection / IP rating
Process Connection1 to 34 to 1011 to 35
10-30VDC; 3-wire PNPPlug M12, IP65/67Tri-Clamp DN25-40 (1..1-1/2")430.-400.-378.-FTL33-AA4M3AB3CJ
Tri-Clamp DN50 (2")430.-400.-378.-FTL33-AA4M3AB3EJ
Accessories1 to 34 to 1011 to 35
M12 right-angle plug with 4-core, 5m PVC cable30.-52010285

Prices are net, ex store Auckland, GST additional and valid until 30/9/2016.
EMC's standard Terms and Conditions of Supply are applicable.


The Liquiphant FTL33 is a point level switch for universal use in all liquids. It is used preferably in storage tanks, mixing vessels and pipes, where the internal and external hygiene requirements are particularly stringent. The reliable switching function works independently from product characteristics such as conductivity and dielectric constant value.


A piezoelectric drive causes the tuning fork of the Liquiphant FTL33 to vibrate at its resonance frequency. When the tuning fork is immersed in a liquid, its intrinsic frequency changes due to the change in density of the surrounding medium. The electronics system in the point level switch monitors the resonance frequency and indicates whether the tuning fork is vibrating in air or is covered by liquid. A signal is output via the DC-PNP electrical connection.

Application Example

The point level switch can be installed in any position in a vessel, pipe or tank, e.g., as overfill prevention or upper level detection (1), lower level detection (2) or dry running protection for pump (3)

Technical data

DC-PNP version (AC/DC version on request)
  • Supply voltage

10 to 30 V DC, 3-wire

  • Switching capacity

200 mA

  • Current consumption
<15 mA
  • Electrical connection

M12x1 (others on request)

Output general
  • Switching delay
0.5 s when tuning fork is covered

1.0 s when tuning fork is uncovered

  • Hysteresis

max. 3 mm

  • Process connection

Tri-Clamp ISO2852 DN25-38 (1...1½");

Tri-Clamp ISO2852 DN40-51 (2");

(others on request)

Operating conditions
  • Orientation
As required
  • Switch point
Vertical orientation: 13 mm

horizontal orientation: 10.5 mm

(water +25 °C, 1 bar)

  • Pipe extension
Length depending on the selected process connection
  • Surface roughness
Metallic surface in contact with process:

Ra ≤1.5 μm (59 μin), EHEDG

Ra ≤0.76 μm (30 μin), EHEDG, 3-A

  • Ambient temperature

–40 to +70 °C

  • Process temperature

–40 to +150 °C

optionally to +100 °C

  • Process pressure

–1 to +40 bar

  • Storage temperature

–40 to +85 °C

  • Climate class

DIN EN 60068-2-38/IEC 68-2-38: test Z/AD

  • Density

> 0.7 g/cm³ (optionally: > 0.5 g/cm³)

  • Viscosity
1...10000 mPa·s, dynamic viscosity
  • Degree of protection

IP65/67 NEMA Type 4X Enclosure (M12 connector);

(others on request)

  • Electromagnetic compatibility
Electromagnetic compatibility in accordance with all relevant requirements of the EN 61326 series and NAMUR recommendation EMC (NE21). For details, refer to the EC Declaration of Conformity
  • WHG approval

Overfill detection system: Z-65.11-531

Leak detection system: Z-65.40-532

  • 3-A, EHEDG
depending on selected product configuration

a) DIN11851 DN25; DN32; DN40 (on request)

b) Tri-Clamp ISO2852 DN25-38; DN40-51

c) Flush-mounting in weld-in adapter RD52 (on request)


Installation according to instruction manual

Electrical connection

Electronic version 3-wire DC PNP

a) M12 connector

b) Valve plug (on request)

c) Cable (on request)

Technical Datasheet