Function And System Design; Measuring Principle; Measuring System - Endress+Hauser Liquipoint T Series Technical Information

Liquipoint T FTW 31, FTW 32

Measuring principle

Measuring system

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Endress + Hauser

Function and system design

An alternating voltage exists between the rod probes in an empty tank.
As soon as the conductive liquid in the tank creates a connection between the ground probe rod
and, for example, the maximum probe rod, a measurable current flows and the Liquipoint T
switches. With level limit detection, the Liquipoint T switches back as soon as the liquid clears the
maximum probe. With two-point control, the Liquipoint T does not switch back until the MAX and
MIN probe is cleared.
Using alternating voltage prevents corrosion of the probe rods and electrolytic destruction of the
product. The material used for the tank walls is not important for measurement because the
system is designed as a closed potential-free circuit between the probe rods and the electronics.
There is absolutely no danger if the probe rods are touched during operation.
Probes with integrated electronic insert (compact-instrument version)
The measuring system consists of:
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FTW 31, FTW 32 with two/three rods or ropes and an electronic insert
•
Control units, switches or signal transmitters, e.g. process control systems PLC, relays, etc.
FTW 31
1 - 2 points
2 - 3 rods
FTW 32
1 - 2 points
2 - 3 ropes
Independent of the tank material
Note!
The compact-instrument version with three probes or rods is always used in ∆s mode.
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