The compact microprocessor operated transmitter / controller measures and controls the pH value in aqueous solutions. It is available as a panel-mounted device according to DIN 43 700 or in a IP 65 field housing. Its simple operation and user-friendly programming allow universal service in almost all areas of industrial applications. The transmitter is fitted with two analogue and two binary inputs. The first analogue input is suitable for connecting a pH combined electrode. A Pt 100 resistance thermometer can be connected to the second analogue input. The device has two 4-digit, 7-segment displays for indicating pH value (red) and temperature (green). The displays show comments during programming, to facilitate the operation. The two control 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 contacts, one binary output and one analogue output is available. To simplify programming and operation, the controller parameters and configuration data have been assigned in different levels. erating level rameter level nfiguration level The levels are secured with pass words against unauthorized access. Membrane keys ensure simple and user-friendly operation. Both LEDs show parameter symbols and values. The device can be switched from pH to ORP measurement. A complete measuring device comprises: e pH transmitter model APM-Z pH combined electrode model APS-Z with integrated or separate temperature sensor Pt 100 model AZT-Z suitable pH measuring cable model APK-Z as well as one of the following: ansmitter wall (AZM-Z1) or pipe mounting (AZM-Z2) accessory. ow or immersion assembly for installation and protection of the electrodes (see accessories)