Emerson Process Management has announced a 12 V dc DPDT relay version of its Rosemount 2120 vibrating fork level switch for automated level monitoring and overspill protection of tanks or vessels in remote locations. The new switch is the first low power switch to provide a built-in relay output, eliminating the need for a separate switching relay.

The 12 V switch is ideally suited to installations where there is no access to normal 24 V power supplies and the only power available is from batteries or solar charged systems. The new switch has all the features of the standard versions, including built-in instrument health/self-checking diagnostics, but is uniquely designed for use in 12 V low power circuits.

To improve safety and maximise operational efficiency, there is an increasing need for automated level monitoring technology to provide overspill protection on tanks and vessels. These installations are often in remote locations where there is no access to normal power supplies. Installing power cabling is often difficult and costly so batteries and solar power provide a convenient and cost-effective alternative.

Based on vibrating short fork technology, the 12 V 2120 is suitable for virtually all liquid applications and is unaffected by flow, turbulence, bubbles, foam, vibration or product variations. The unique ‘Fast Drip’ fork design provides quicker and more reliable detection, especially in high-density liquids. Electronic self-checking and condition monitoring with Heartbeat LED give status and health information on the fork and sensor.

An adjustable switching delay virtually eliminates the risk for false switching in turbulent or splashing applications and the range includes various housings and wetted parts materials, with a complete range of process connections, extended fork lengths and overfill approvals.

The optional two-inch NPT thread eliminates the need to adapt existing fittings to fit smaller connections and with no moving parts to wear or stick, the Rosemount 2120 provides a low maintenance alternative for applications previously using float switches, conductive, capacitive, and optical sensors. With a temperature range up to 150°C (302°F) and pressures up to 100 bar-g (1450 psig), the 2120 is ideally suited to harsh process conditions, including hazardous area installations.