Omron 61F-GP-NH AC100 High/Low Level Controller, 100VAC, SPD

The Omron 61F-GP-NH AC100 is a conductive-type level controller from the 61F series, wired for high/low level detection in tanks or sumps. It operates on a 100VAC supply and uses the conductivity of the liquid between two or three probe electrodes to sense the level — no floats, no moving parts in the tank. The relay output (SPDT, 2 Form C, rated 3A @ 250VAC) switches a pump or valve based on the fill/drain logic selected by the wiring configuration between the common and high/low terminals. Sensitivity is adjustable across 10kOhm ~ 40kOhm, which means it can be tuned for different liquid conductivities — from relatively conductive tap water (lower resistance) up to less conductive fluids like distilled water or some chemical solutions (higher resistance). The sensor-to-controller distance can run up to 50m, so the controller can be panel-mounted well away from the vessel. It mounts on an 11-pin octal socket, making it quick to swap for maintenance or replacement.