The Omron 61F-HSL AC100 is a High/Low Level controller from the 61F series, designed to detect and control liquid levels in tanks, reservoirs, or sumps using conductive probes. It operates on a 100VAC supply and features an adjustable sensitivity range of 0 to 5 MΩ, meaning you can tune it to detect liquids with different conductivity levels — from tap water to demineralized water or even some chemicals — without false triggering on foam or residue. The output is a SPDT relay (2 Form C) rated at 5A at 220VAC, so it can directly switch a pump contactor, alarm, or solenoid valve without an intermediate relay.
Mounting and wiring reality
This unit is socketable — it plugs into an 8-pin octal base (sold separately), which means you can pre-wire the base in the panel and swap the controller in seconds if it fails. The termination style is a plug-in 8-pin octal, a standard footprint shared with many industrial relays and timers, so the panel layout is straightforward. Operating temperature range of -10°C to 55°C covers most indoor control cabinet environments but watch for mounting near steam pipes or hot process vessels that could push the ambient above 55°C.