Digital sensors are revolutionising process measurement technology

Communication between sensors and controllers used to be based on analogue current and voltage signals. As these signals depend on the parameter to be measured, it was rarely possible to operate different sensors using just one controller. Modern digital sensors, on the other hand, function completely self-sufficiently. They transmit the measured values digitally, together with the associated unit (e.g. 1.5 mg/l O2), to the controller. The advantages are obvious; any desired combination of sensors can be connected to a single controller. This simplifies both operation and spare parts administration. Moreover, digital communication between different controllers in a single network makes all measured values accessible at every one of the plant’s measuring stations and enables them to be transmitted to a central control room This article introduces the HACH LANGE digital controller platform.