Overview
The Nohken FR21S-4P is a magnetic float level sensor designed for point-level indication in industrial and process applications. This compact model employs hermetically sealed reed switch technology housed within the stem, with a permanent magnet integrated into the float mechanism. As the liquid level changes, the magnet actuates the reed switch, providing reliable electrical signaling for pump control, valve actuation, and alarm functions.
Key Features
- Hermetically sealed reed switch for long service life and reliability
- Compact FR21 form factor ideal for space-constrained installations
- Magnetic float design insensitive to pressure, temperature, and specific gravity variations
- Simple electrical interface for direct integration with PLCs and control systems
- On-site adjustable set points and switch direction configuration
Technical Specifications
- Model: FR21S-4P
- Sensor Type: Magnetic float with reed switch
- Electrical Rating: 15VA @ 1A
- Switch Type: Hermetically sealed reed switch
- Float Design: Magnetic permanent magnet actuator
- Material Compatibility: Available in standard and specialized materials (316SS, fluorine resin, titanium upon request)
- Operating Principle: Float level change actuates internal reed switch
- Set Point Adjustment: Field-adjustable on installation
Typical Applications
- Petrochemical processing and refining operations
- Water treatment and wastewater control systems
- Food and beverage production facilities
- Chemical manufacturing and storage tank monitoring
- Pump and valve control for industrial process automation
- High-temperature and pressure vessel level indication
Compatibility & Replacements
Compatible With
- Industrial PLC systems (Allen-Bradley, Siemens, Mitsubishi, Omron)
- Standard 24 VDC control circuits
- Discrete input modules on automation controllers
- Mechanical pump and valve control systems
Replaces / Drop-In Replacement For
The FR21S-4P is part of the Nohken FR21 series. Verify compatibility with your system integrator before ordering to ensure proper mechanical mounting and electrical specification match.
Works With
- SCADA and HMI systems via discrete digital inputs
- Relay logic and hardwired control circuits
- Standard industrial control panels
- Automation frameworks supporting 15VA reed switch inputs
