The Rosemount Liquid Level Switch is designed using the principle of a tuning fork. A piezo-electric crystal oscillates the forks at their natural frequency. The frequency of the vibrating fork sensor changes depending on the medium in which it is immersed. The denser the liquid, the lower the frequency. When used as a low-level alarm, the liquid in the tank or pipe drains down past the fork, causing a change of natural frequency that is detected by the electronics and switches the output state. When 2110 is used as a high-level alarm, the liquid rises in the tank or pipe, making contact with the fork which then causes the output state to switch.

Materials of construction is 316/316L Stainless Steel (1.4401/1.4404) dual certified
Process connection size is 1in BSPT (R) thread
Relay DPCO, 20 to 264 Vac 50/60Hz, 20 to 60 Vdc
Standard surface finish
Housing has glass filled nylon and M20 conduits/cable threads
Fork length is standard length of 1.7in (44 mm)

Function virtually unaffected by flow, bubbles, turbulence, foam, vibration, solids content, coating products, liquid properties, and product variations
Operation temperatures ranges from –40°C and 150°C
A ’heartbeat’ LED indicates its operating state, LED also flashes when the switch output is ’off’ and is constantly lit when 'on'
Adjustable switching delay prevents false switching in turbulent or splashing applications
’Fast drip’ fork design gives quicker response time, especially with viscous liquids
Rapid wet-to-dry and dry-to-wet time setting for highly responsive switching
Fork shape is optimized for polishing to meet hygienic requirements
Mechanical- and electro-polishing options
Magnetic test point makes functional test easy
No moving parts or crevices for virtually no maintenance
Specific extended fork length is factory default length (only if Fork Length A or H is selected)

Overfill protection
High and low point level alarms
Pump control or limit detection
Run dry or pump protection
Hygienic applications
High-temperature applications
Wireless applications
Most liquids including coating liquids, aerated liquids, and slurries

ATEX Intrinsic Safety