Solid Level Switch - Vibrosonde

Vibrosonde vibrating rod type level switches are compact level limit switches for free-flowing as well as for bulk solids. They are also available in flameproof enclosures suitable for hazardous areas.


A vibrating rod is kept in mechanical vibrations at its resonance frequency by piezo-electric crystals. When the service material covers the rod probe, vibrations are damped which is sense electronically and processed signal is used for switching.

  • Low power consumption, less heat, durability
  • Fast switching
  • Self-diagnosis
  • Independent of material’s electrical properties
  • Universal Power Supply: 19-265 V AC & 11-55 V DC
  • Suitable for High temperatures up to:
    • H1: 150°C
    • H2: 200°C
  • Immunity to spurious external vibrations
Mechanical Specifications

 Resonant Frequency

  • ____ Hz to ___ Hz

Probe Length

  • Extensible probe lengths from 250mm up to 3 meters


  • W: Weatherproof
  • P5: IP-65 Weatherproof Housing
  • FA: Flameproof for Gas Group IIa and IIb
  • FC: Flameproof for Gas Group IIc

Process connections (Mounting Arrangement)

  • Threaded Mounting: 1-1/2” BSP, 2” BSP / NPT
  • Flange Mounting: As per specification

Extension Length

  • Pipe GI / SS: 250mm to 3 meters

Probe Length

  • Extension Length + Rod Length

Wetted Parts and Mounting Material

  • S4: SS – 304
  • S6: SS – 316

Process Temperature

  • A (Ambient): below 100°C
  • H (High temperature): up to 150°C
Electrical Specifications

Input power supply & Outputs

  • D: Universal Power Supply 18-55 V DC, 90-265 V AC, Single-point two potential free relay outputs rated at 6A
  • S: Universal Universal Power Supply 18-55 V DC, 90-265 V AC
    • Singe-point – Single relay(Rated 6A)
    • Open-collector PNP output, max 100mA non-inductive load
  • M: 24VDC – 8/16 mA 2-wire Loop powered current output
  • N: 8.2V Namur type current output (ION = 2.2 … 2.5 mA, IOFF = 0.8 … 1.0 mA)

Namur compliance can be attained with a Namur certified isolator.

Power Consumption

  • Less than 3 VA

Fail-safe settings

  • Field selectable (through toggle switches)
  • Open: Fail-safe High, Close: Fail-safe Low

Response Time

  • 1 sec: When covered
  • 2-3 sec: When uncovered

Time Delay Settings

  • Cover and Uncover delay: 1s/3s to 20s, through toggle switches

Sensitivity Settings

  • Field selectable : Through toggle switches
Applications Specifications

 For all Industries requiring level limit detection in Free Flowing solids including:

  • Powders, sand, sugar
  • Pulverized coal
  • Food grains
  • Cement
  • Granular material
  • Flameproof Housing IIa / IIb / IIc certified by CMRI, Dhanbad
  • Flameproof Housing IIc certified by CMRI, Dhanbad
  • IP-68 from ETDC Indore
  • ISI mark from the Bureau of Indian Standards
Switching Indication
  • 2 LED’s
  • Red: Alarm, Green: Normal