Endress+Hauser Liquipoint FTW 31 User Manual

Technical Information
TI 375F/00/en
Level Limit Detection in Liquids
liquipoint T FTW 31, FTW 32
Level limit switch for multiple point detection
in conductive liquids
Applications
Liquipoint T sensors are used in
conductive liquids (as of 10 µS/cm) for
determining level limits.
Depending on the number of measuring
points (up to 5 rods or ropes), measuring
tasks such as overspill protection, dry
running protection, two-point control of
pumps or multiple point detection can be
implemented for an existing process
connection.
Your benefits
• Detect up to five level limits with one
probe
• Two-point control and additional
maximum and minimum detection
• Option between rod or rope version for
optimum adaptation to the application
• Flexible instrumentation:
– with built-in electronic insert, either
transistor or relay output for 2 or
3 rod/rope probes
– for connection to a separate
transmitter power supply unit
• No calibration required;
standard setting for the most common
conductive liquids
• No moving parts in the tank:
– long service life
– reliable operation with no wear or
blockages
• WHG approval
• Four measuring ranges can be set
100 Ω, 1 kΩ, 10 kΩ, 100 kΩ
• Cost-effective probe for conductive
liquids
• Electronic inserts for:
– NAMUR output
– Relais output
– Transistor output

Endress+Hauser Liquipoint FTW 31 Specifications

General

Manufacturer	Endress+Hauser
Application	Level detection in liquids
Material	Stainless steel, PTFE
Process Connection	Threaded, Flanged
Protection Rating	IP68
Output	PNP

Summary

Level Limit Detection in Liquids

Function and System Design

Measuring Principle

Explanation of how the alternating voltage between probes detects liquid levels.

Measuring System Configurations

Overview of system setups with integrated and separate electronic inserts.

Output and Electronic Inserts

Electronic Insert FEW 52 (DC-PNP)

Details on the FEW 52 insert, its output signal, and fail-safe modes.

Electronic Insert FEW 54 (Relay)

Information on the FEW 54 insert, relay output, and associated settings.

Electronic Insert FEW 58 (NAMUR)

Specifications for the FEW 58 insert, NAMUR output, and fail-safe operation.

Compact Instrumentation Details

FEW 54 Relay Output Implementation

Detailed description of the FEW 54 relay output circuit and load handling.

FEW 58 NAMUR Output Implementation

Detailed description of the FEW 58 NAMUR output circuit and signal transmission.

Mechanical Construction

Design and Dimensions

Detailed drawings showing dimensions for rod and rope probe versions.

Human Interface

Operating Elements and Settings

Display Elements and Status Indicators

Ordering Information

FTW 31 Product Selection Codes

Guide to selecting the correct product code for FTW 31 based on features.

FTW 32 Product Selection Codes

Guide to selecting the correct product code for FTW 32 based on features.