Function And Features; Functional Overview - IFM Electronic LR7022 Bedienungsanleitung Und Sicherheitshinweise

Function and features

Applications
LR70 is a compact level sensor for the detection of liquids. The unit
was specially designed to meet the requirements of machine tool
building. It is specially suited for monitoring coolant emulsions as well
as aqueous cleaning agents in part cleaning systems.
Restriction of the application area
• Only use the unit in metal tanks.
Not suited for plastic tank covers.
• The unit is not suitable for oils, fats, granulates, bulk materials,
acids, alkalis; it is not suitable for food and electroplating applica-
tions.
• Foam, separate layers (e.g. oil on water), highly absorbing or bub-
bling surfaces can lead to incorrect measurements or signal loss.
Check the function by an application test.
In case of signal loss, the unit displays "Err1" and switches the outputs to
a defined state → page 41, output response).

Functional overview

Measuring principle
The unit operates to the principle of guided wave radar: It measures the
level using electromagnetic pulses
in the nanosecond range.
The pulses are transmitted by the
sensor head and guided along
the probe (fig. 1). When they hit
the medium to be detected they
are reflected and guided back to
the sensor (fig. 2). The time
between transmitting and receiv-
ing the pulse directly relates to
the travelled distance and the cur-
rent level.
The reference for distance measurement is the lower edge of the
thread.
1 2
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