LI213x
Binary level sensor for overflow prevention / leakage detection according to WHG
6
4 Function
4.1 Measuring principle level
The device operates on the capacitive measuring principle. It detects by direct contact with the
medium whether the requested level (point level) is reached.
The relative permittivity of a medium is important for its detection (formerly: dielectric constant). Media
with a relative permittivity greater than 1.8 are reliably detected.
Electrically conductive and non conductive media are detected.
Relative permittivity (dielectric constant) of common media
Mineral oil
≈ 2
Coolant emulsion
≈ 25...75
Glycol
≈ 37
Water
≈ 80
1
The device operates with radial detection characteristics. Therefore,
media below the active zone (1) are not detected.
When perfectly adjusted, the presence of certain media can be detected while build-up or foam
is suppressed.
4.2 Measuring principle temperature
The temperature is detected by a temperature element at the lower end of the probe and electronically
evaluated.
4.3 Features of the device
•
The device versions are offered with different probe lengths.
•
Point level selectable by the installation length.
•
Parameter setting via teach button or IO-Link.
•
The device has two switching outputs:
– Output OUT-OP is permanently assigned to the process value level (limit level) and is
permanently designed as normally closed.
– Output OUT2 can be assigned to either the process value level (limit level) or temperature and
can be programmed as normally closed / normally open.
•
Adjustment function (empty and full adjustment) to the medium to be detected.
•
Defined state in case of a fault.
