The Rosemount 2120 is a vibrating fork level switch designed to detect whether a liquid has reached a predefined level. The fork vibrates at its resonant frequency in air. When immersed in liquid, the change in vibration frequency is detected by the electronics, which changes the switch output to indicate the level condition.
With no moving mechanical parts and no routine field calibration requirement, the Rosemount 2120 offers a practical solution for industrial level alarms and control. Its adjustable switching delay helps reduce false switching caused by turbulence or splashing, while the heartbeat LED and magnetic test point simplify device-status checks and functional testing.
Key Features
- Vibrating fork technology for dependable point-level detection
- High- and low-level switching for liquid process applications
- No moving mechanical parts for reduced mechanical wear
- No field calibration required for normal operation
- Adjustable switching delay to help prevent false switching in turbulent conditions
- Fast-drip fork design for quicker response, particularly in viscous liquids
- Heartbeat LED for visual device-status indication
- Magnetic test point for convenient functional testing
- SIL 2 safety certification for specified safety-related applications
- Optional hygienic approvals for suitable sanitary configurations
- Optional 12 VDC version for solar- or battery-powered installations
Suitable Applications
- Tank high-level and low-level alarms
- Overfill prevention
- Pump protection and dry-run prevention
- Chemical processing
- Oil and gas processing
- Water and wastewater treatment
- Food and beverage production
- Pharmaceutical and hygienic processes
- Liquid storage vessels
- Pipeline and process equipment monitoring
Technical Highlights & Selection Considerations
- Detection principle: The switch detects changes in fork vibration when the fork becomes immersed in liquid.
- Liquid compatibility: Verify material compatibility and the suitability of the selected fork and process connection for the liquid being measured.
- Process conditions: Check the allowable operating temperature and pressure for the exact model and process connection.
- Switching delay: Select an appropriate delay for applications involving turbulence, splashing, or rapidly changing liquid levels.
- Installation: Confirm that the selected fork length and mounting arrangement suit the vessel, nozzle, and process conditions.
- Electrical output: Output types and electrical supply requirements depend on the selected configuration.
- Safety applications: SIL 2 certification applies to specified configurations. Confirm the exact model certification and follow the applicable safety manual.
- Hygienic requirements: 3-A, EHEDG, FDA-related compliance, and ASME-BPE-related options depend on the selected configuration and applicable requirements.
- Remote power: Solar or battery operation requires the compatible 12 VDC version and a suitable power arrangement.
- Device testing: The magnetic test point supports functional testing; follow the manufacturer's instructions for the selected installation.
Frequently Asked Questions
Q1: What is the Rosemount 2120 used for?
It detects whether a liquid has reached a preset high or low level in a tank, vessel, or pipeline and provides a switching signal for alarms or control systems.
Q2: How does the Rosemount 2120 work?
Its fork vibrates at a resonant frequency. When liquid covers the fork, the frequency changes, and the electronics detect this change to switch the output.
Q3: Does the Rosemount 2120 require calibration?
It does not require routine field calibration for normal operation. Follow the manufacturer's instructions for installation, functional testing, and maintenance.
Q4: Can the Rosemount 2120 operate in turbulent liquids?
Yes. Its adjustable switching delay helps reduce false switching caused by turbulence and splashing. Suitability still depends on the actual process conditions.
Q5: Is the Rosemount 2120 suitable for safety applications?
Specified configurations are independently certified to IEC 61508 for SIL 2 applications. Verify the exact certification and ensure the complete safety instrumented function meets the required safety standards.
Q6: Is the Rosemount 2120 suitable for hygienic applications?
Selected configurations offer hygienic approvals for applications such as food and beverage processing. Confirm the required approvals, process connection, and cleaning requirements before ordering.
