Mercury-activated, narrow-angle float switch designed to activate pump control panels and alarms. This narrow-angle sensing device is used to accurately monitor liquid levels in sewage and non-potable water applications. The Sensor Float® control switch is not sensitive to rotation and is suitable for use with intrinsically safe circuits. Contact SJE Rhombus regarding specific intrinsically safe applications. Normally Open Model (high level), the control switch turns on (closes) when the switch tips slightly above horizontal signaling a high level and turns off (opens) when the switch drops slightly below horizontal.