The Omron 61F-G2NR AC110/220 is a High/Low Level controller from the 61F series, designed for conductive liquid level detection in tanks, reservoirs, and process vessels. It operates on a 110/220VAC supply and provides two relay outputs — one SPDT (1 Form C) and one SPDT (2 Form C) — for alarm or pump control. The sensitivity adjustment range of 0 to 1.1 kΩ lets you tune the detection threshold for different liquid conductivities, and the control-to-sensor distance reaches up to 800 m, suitable for remote tank farms or well sites.
Mounts directly on standard DIN rail (snap-on). The two-wire/three-probe feature means you can use either a two-electrode or three-electrode probe configuration — three-probe gives you a reference electrode for more stable detection in conductive liquids. The alarm-high contact output triggers when the liquid level rises above the high probe, so you can wire it to a horn or PLC input.
The relay contacts are rated 3 A at 200 VAC — enough to switch a small pump contactor or alarm beacon directly, but for larger loads you'd interpose a contactor. The 0 to 1.1 kΩ sensitivity range covers most conductive liquids (water, weak acids, coolants); if the liquid is very pure (deionized water), you may need a lower-resistance probe or a different controller. Operating temperature of -10°C to 55°C means it's fine for indoor panel use but not for outdoor enclosures in freezing climates without a heater.