The GESTRA NRS 1-50 and NRS 1-51 are compact, electronic level switches designed for reliable monitoring of conductive liquid levels, particularly in steam boiler applications. The NRS 1-50 functions as a level switch, often used for water level limiting, while the NRS 1-51 serves as a high or low-level alarm. Operating with a single electrode, these devices ensure safe and efficient plant operation by preventing low-water conditions or overfilling. Housed in a durable, DIN rail mountable enclosure, they feature adjustable sensitivity settings and a fixed time delay to prevent false switching from turbulence. Their wide-range supply voltage makes them versatile for various industrial control systems.