Process Control Instruments and Field Devices
  • Overview
  • Features
  • Specs
  • Literature

EH Liquiphant FTL31 Vibronic Point Vibration Level Switch for liquids. Robust stainless steel housing and compact design. Not suitable for hazardous areas. LED indicator. CSA approval.

Part# with Options:        FTL31-AA4M2AAVAJ
Price with Options:        Please Email us your request for quote   


(1) Approval for EH FTL31 & FTL33
Power Supply
(2) Power Supply for EH FTL31 & FTL33
Electrical Connection
(3) Electrical Connection for EH FTL31
Sensor Design
(4) Sensor Design for EH FTL31
Sensor Type
(5) Sensor Type for EH FTL31
Process Connection
(6) Process Connection for EH FTL31

  Availability 10 Days  ]


The Liquiphant FTL31 is a point level switch for liquids and is used in tanks, vessels and pipes.

It is used for overfill prevention or pump protection in cleaning and filter systems as well as in cooling and lubrication vessels, for instance.

Ideal for applications in which float switches or conductive, capacitance and optical sensors have been used up to now. The Liquiphant FTL31 also works in areas where these measuring principles are not suitable due to conductivity, buildup, turbulence, flow conditions or air bubbles.

The Liquiphant FTL31 can be used for process temperatures up to:

  • 100 C (212 F)
  • 150 C (302 F)

Not suitable for hazardous areas.

The use of the Liquiphant FTL33 is recommended for hygiene areas.

Your benefits
  • Operational safety, reliability and universal application thanks to the tuning fork measuring principle
  • Robust stainless steel housing (316L)
  • External function test with test magnet
  • Onsite function check possible thanks to LED indication
  • Compact design for easy installation even in confined conditions or hard-to-access areas
Measuring principle

A piezoelectric drive causes the tuning fork of the Liquiphant FTL31 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 or AC/DC electrical connection.

Measuring system

The measuring system consists of a Liquiphant FTL31 point level switch, e.g. for connection to programmable logic controllers (PLC), a mini-contactor or solenoid valve.

Measuring PrincipleVibration Liquids
Characteristic / ApplicationLevel switch for liquids and is used in tanks, vessels and pipes.
Supply / Communication20 ... 253V AC/DC, 2-wire
10 ... 30V DC-PNP 3-wire
Ambient temperature-40 C ... 70 C
(-40 F ... 158 F)
Process temperature-40 C ... 150 C
(-40 F ... 302 F)
Process pressure absolute / max. overpressure limitVacuum ... 40 bar
(Vacuum ... 580 psi)
Min. density of medium>0,7g/cm
(>0,5g/cm optional)
Main wetted parts316L
Process connectionThreads:
G1/2, G3/4, G1, MNPT1/2, MNPT3/4, MNPT1, R1/2, R3/4, R1
CommunicationAC/DC, DC-PNP
Certificates / ApprovalsCSA C/US
Safety approvalsOverfill prevention WHG
Design approvalsEN 10204-3.1
Marine approvalABS/ LR/ BV/ DNV
OptionsAdjustment switching delay
Cleaned from oil+grease,
PWIS free
Export Info
Harmonized Tariff Code (HTC)9026107000

    FTL325P-O1A1 EH Nivotester FTL325P Vibronic Point level switching unit for connection to Liquiphant or Soliphant. DIN-Rail. Intrinsically safe signal circuit. SIL3 safety approval. ATEX, FM and CSA approvals. ..

    FTL375P-F1E1 EH Nivotester FTL375P Vibronic Point level switching unit for connection to Liquiphant or Soliphant. 19" circuit board. Intrinsically safe signal circuit. 20-30VDC. Racksyst 4HP Housing. SIL3 safety approval. ATEX approval. ..

B2B Checkout Options: Designated Carrier and Tax-Exempt purchase
Payment Options: Credit Card, Credit Card Over the Phone, PAYPAL, Wire Transfer and Check

Checkout with Paypal Visa MasterCard Amex Checkout with Wire Transfer Electronic Payment

> GENERAL PURPOSE :    5 Items found.


EH Liquipoint FTW23 Capacitance Point level switch for water-based liquids in hygienic applications. 316L Sensor. G1 to G3/4 Thread Process Connection. CSA C/US Approval.



EH 11371 One rod probe for point level detection of conductive liquids in the food industry. 316Ti Rod. G 1 1/2 Process Connection. Relay Communication.



EH Liquiphant FTL33 Vibronic Point Vibration Level Switch for liquids in the food sector. Robust stainless steel housing. CIP and SIP cleanability guaranteed. LED indicator. 3-A and EHEDG certificates.



EH Liquipoint FTW33 Conductive Point level very compact probe for liquid and pasty media in hygienic applications. Flush-mounted. 10-30VDC. 316L Sensor. 3-wire PNP Output. G1 to G3/4 Thread Process Connection. CSA C/US Approval.



EH Pump Protection FTW360 Conductive Point level probe for liquids. Flush-mounted. G3/4 Process Connection. 316Ti/PTFE Insulation. Relay Communication.