Solutions for Industries and Automation
ABB Measurement and Analytics - Quad Industry GmbH

RS85 – ABB Vibrating Fork Level Switch

vibratingThe resonator utilizes a piezoelectric driven tuning fork that exhibits a large change in resonant frequency when immersed in any liquid. A “smart” microprocessor-based electronic unit keeps the sensor in a resonant state as it changes from dry to wet or wet to dry.


  • Direct Replacement for Ultrasonic Gap Switches, RF Capacitance Switches, Float Switches and Other Technologies
  • Immune to Coating or Build-Up on Sensor
  • Robust Sensing Element
  • ¾” and 1” (NPT, BSPT) Process Connections
  • Choice of International Flanges and Range of Tri-Clamp Fittings and Probe Finishes
    • Temperatures between -40oF to 350oF (-40oC to 177oC) with HT6 High Temp Ext.
    • Pressures to 2000 psig (138 bar)
    • Viscosity up to 20000 cP
    • Density from 0.45 to 2.0
  • Single or Dual Compartment Housing with Viewing Cover
  • Field Selectable Parameters with External Magnet or Internal Pushbuttons (Fail Safe, Density, Time Delay)
  • Modular Electronics with Alarm Status LED
  • Self-Test Diagnostics
  • Extended Probe Lengths to 120 in (3048 mm)


  • Hermetic Seal Probe and Housing
  • Special Alloy Sensors (Hastelloy) and Halar/PFA Coating for Chemical Resistance
  • Remote Mount Electronics
  • Low / High Pressure Packing Glands

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