The compact microprocessor transmitter/controller measures and controls the conductivity in aqueous solutions. It is available as a panel-mounted device according to DIN 43 700 or in a field housing. Its simple operation and user-friendly programming allow universal service in almost all areas of industrial metrology. The transmitter is fitted with two analogue and two binary inputs. The first analogue input is suited for connecting conductive conductivity measuring cells with cell constants 0.01; 0.1; 1.0; 3.0 and 10.0 1/cm, depending on the desired measuring range (see table "Cell constant and measuring range"). A Pt 100 resistance thermometer may be connected to the second analogue input. The device has two 4-position, 7-segment displays for indicating conductivity (red) and temperature (green). The display show comments during programming. The two controller relays can be configured as limit value and/or pulse lengths or pulse frequency controllers with P, PI, PD or PID structure. A maximum of two relay make contacts, one binary output and one analogue actual-value output is available. To simplify programming and operation, controller parameters and configuration data have been assigned to different levels.