Control circuit devices and switching elements proximity sensors, d.c. interface for proximity sensors and switching amplifiers (NAMUR)

This standard applies to proximity sensors connected for operation by a two-wire connecting conductor to the control input of a switching amplifier. The switching amplifier contains a d.c. source to supply the control circuit and is controlled by the variable internal resistance of the proximity sensor. Note 1. These devices can be used in an explosive atmosphere if they also comply with EN 50020 "Electrical equipment for explosive atmospheres and intrinsic safety 'i'". 2. These devices have been defined by the German organization "Normenausschuss für Mess-und Regelungstechnik (NAMUR)"