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INTRODUCTION
The LTDR series are 4-wire TDR-Sensors (time domain reflectometry), also known as
Guided Radars or Guided Wave Radars, with single rod, coaxial probe or rope probe for
continuous level measurement and point level detection in liquids, with analog and
switching output.
This document gives instructions for mounting, wiring, and basic configuration of LTDR.
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MOUNTING
LTDR is mounted vertically to the tank via its connection thread, which is screwed directly
into a standard threaded tank connection, i.e. weld-in socket, or it can be screwed into a
flange, which is then connected to a tank nozzle.
LTDR should not be welded directly into the tank. Neither should flanges be welded onto
LTDR. Welding on the metal parts of LTDR will cause serious damage to the sensor.
Do not lift or handle LTDR by its probe; this can cause excessive stress on the probe
connection. LTDR should be handled by the hexagon or the lower section of the housing.
Do not screw in LTDR by its housing; it should be tightened only via its hexagon (wrench
size 32 mm for connection thread G3/4A).
Tighten the coaxial probe only at its lower hexagon; the upper hexagon of the coaxial
probe is not needed for mounting.
The customer has to ensure proper sealing of the sensor connection; based on his
process conditions like temperature, pressure and resistance against his process liquids
and atmosphere.
G thread connections require a suitable gasket for pressure-tight joints.
The G3/4A connection thread of LTDR is supplied with a gasket made of Klingersil C-
4400, thickness 2 mm. The suggested tightening torque for this thread size, this type of
gasket, and a process pressure of max. 40bar is 25Nm (maximum permissible torque: 45
Nm).
For NPT thread connections, pressure-tight joints require a sealant directly on the
threads.
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Figure 1. Mounting
