KROHNE LS 72xx EN - Manual (Page 11)

02/2013 LS 72xx 11
6 Product description
6.1 Applications
The conductive mono-rod-level sensors of the LS Series are designed to detect the
level of conductive liquids. Since the rod electrodes can be shortened to any
required length, this allows flexibility in the choice of the operating point.
6.2 Functional principle
Conductive measuring sensors pick up the electrical resistance of the tank product
when the electrode is immersed in the product. This causes a small alternating
current to flow which is measured by the electronic unit in the converter module. The
wall of the vessel or pipe acts as reverse potential. The switching position is defined
by the length or mounting position of the sensor.
6.3 Construction
The weldable process sleeve is made of stainless steel and ensures installation in
keeping with hygiene requirements. Various level converter modules (see
Accessories) are available for evaluation purposes. The integrated evaluator module
in the connection head allows direct connection to an SPC or PLC via a short-circuit-
proof 24-V switching signal.
6.4 Features
•
Sensor for hygienic installation, no elastomers
• Compact
design
•
Rod electrode can be shortened to any length
•
Optimized flow geometry
• Precise,
constant operating point
•
Rejection of foam and deposits (coated electrode)
•
Insensitive to vibration
•
Materials in conformity with food standards
• Maintenance-free
•
Installation in pipelines DN 25 and higher
•
Direct connection to an SPC or PLC (with integrated electronics)
•
Hygienic adapter sleeves for other process connections