New Magnetically Coupled Level Gauge Switches with Global Approvals

ABB’s Measurement & Analytics (USA) business has announced the LMS100 SPDT switch for mounting on level gauges. When mounted on an ABB KM26 Magnetic liquid level indicator or any external chamber that contains a magnetic float, the LMS100 switch can sense high or low levels within a vessel. Its unique magnetic coupling action avoids the need for seals, diaphragms, springs, or torque tubes. Magnetic coupling eliminates process contact and connections, ensuring total isolation from the process. Mounting and adjustment is achieved via a small screw driver. The switch housing is entirely 316 stainless steel. The switch has ATEX, IEC, FM, and FM-C hazardous location approvals worldwide.

A form C reed switch within the LMS100 is activated via a rotating permanent magnet. The hermetically sealed reed switch uses precious metal contacts in an inert gas. A magnetic float travelling in a chamber relative to the LMS100 causes the reed switch to change state. The hermetically sealed contacts serve to insure a high degree of hazardous area safety, weather resistance, and general reliability. These trip points can be used for alarms, digital inputs to DCS or PLC, or to control a high-current interposing relay.