Sensor with intelligence - Stephan-C. Köhler

Safe and intelligent: Memosens from Endress+Hauser Conducta captivates with its induction technology and integrated memory chip.

In liquid analysis, the connection between sensor and cable has so far been the weakest point. Memosens from Endress+Hauser Conducta has now found a remedy with a new principle: induction technology ensures maximum fault protection with easy use. At the same time, the Memosens technology, with its wide range of uses, for the first time allows the storage of process-relevant data directly in the sensor. The integrated memory chip guarantees not only complete documentation, but will also allow the direct connection of the measuring point to the Internet.

Measurement variables with very small currents make high demands on the connection between sensor and transmitter. Leaks and corrosion impair the measurement value transfer. In this case, particularly high-resistance measurements in a dirty or damp environment quickly become a problem. In order to minimise as far as possible the voltage drop as far as possible, the use of expensive MIL connectors with gold contacts, complicated special cable and complex measuring amplifier has until now been necessary. However, the systems remained prone to failure.

"Previously, only the symptoms were treated", says Dr. Detlef Wittmer, Manager of F&E at Endress+Hauser Conducta. "Whereas Memosens eliminates the causes of the disadvantages." An inductive connection between cable and electrode allows the hermitic sealing of connector head and coupling, allows bidirectional data transfer and provides the connector head with power. The mechanical and electrical advantages are apparent: there are no longer any contacts at risk of corrosion; dampness is not able to falsify the voltage signal. Cable length and quality are almost irrelevant for the quality of the signal transmission.

The principle of galvanic decoupling from the measuring transmitter simplifies the wiring and at the same time increases electromagnetic compatibility. The plug-in connection between cable and sensor with its bayonet connection is not only easy to handle, but is also very safe. For example, it is no longer possible to unscrew the sensors from process connections unintentionally when releasing the cable.