Smart SSI

Vital – for Solids

Vital vibrating forks are compact level limit switches for free-flowing solids. These come with with explosion-proof housings for applications of hazardous areas.


A specially shaped tuning fork is kept vibrating using piezo-electric elements. The oscillation of the fork damps when in contact with the material. The loss of oscillation amplitude is detected and used for switching a relay. The output contacts of the relay are in turn used for annunciation and/or control.

  • Low Power Consumption: Less heat, Long life
  • Fast switching
  • Self-diagnosis
  • Independent of material’s electrical properties
Mechanical Specifications

Resonant Frequency

Resonant frequency varies with the length of tines:

Fork Length(mm) Min. Probe Length(mm) Frequency(Hz)
185 200 150
100 135 350

Probe Length

  • Extendible probe length from 135 mm
  • 135mm, 185mm – up to 3m


  • W: Weatherproof
  • P5: IP-65 Weather Proof Housing
  • FA: Flame Proof for Gas Group IIa and Iib
  • FC: Flame Proof for Gas Group IIc

Process Connection (Mounting Arrangement)

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

Extension Length

  • Pipe- GI/SS : 200mm – 3000mm

Probe Length

  • Extension Length: + 135mm/185mm

Wetted Parts:

  • S4: SS-304
  • S6: SS-316L
  • PT: PTFE Lined
  • HL: Halar Lined
  • HC: Hastelloy C

Process Temperature

  • A (Ambient): below 100°C
  • H (High temperature): 100°C – 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

  • ____mW

Fail-safe Setting

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

Response Time

  • 0.8s Cover Delay
  • 1s Uncover Delay

Time Delay Settings

  • Cover and Uncover Delay: 0.8s / 1s to 20s, through toggle switches

Sensitivity Setting

  • 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
Switching Indication
  • 2 LED’s
  • Red: Alarm, Green: Normal

Shorter Fork lengths

More value in less

Shorter vibrating forks – minimum insertion length of 135mm, with no compromise in operational ruggedness of the device. Saves space → paves the way for designing smaller tanks / silos.

Better immunity to external vibrations

Though vibrating forks are one of the most easy-to-install instruments, they can be sensitive to vibrations on the application silo / tank or the vibrations in the material. Vital has an intelligent noise cancellation algorithm to avoid spurious switching in case of external vibrations.

100% incubated and tested → serving your application for longer

Each Elixir instrument goes through 5 test points at various stages in its production to ensure compliance with our quality and design. They also go through an early life failure test for at least seven days to ensure that only the best forks are shipped.

A 'switch' in time saves material 'fine'

Reliable and fast switching with an adjustable time delay option from 0.8s to 25s.

Polished finish for hygienic applications

Ensures easy cleaning, helps with stringent hygiene compliances in pharmaceuticals, dairy, and food applications.

Coming Soon

A legacy to reckon with

Sapcon was the first wholly Indian manufacturer to have completely manufactured vibrating forks in India.

Vital is the latest vibrating fork from Sapcon; bettering the legacy vibrating fork models that have been successively improved and placed in the market since 1984.

Innovative range of outputs

Packaging plant manufacturers or OEM’s (Original Equipment Manufacturers) desire outputs suitable to the end-user’s site. Relay and PNP (Open Collector PNP) outputs though standard are generally available only in separate models. Thus, they normally had to be separately procured and stocked.

In a close understanding of our customer behaviour, we have launched a single model with both Relay and PNP output with an input power supply from 24 V DC – 265 V AC on the same two terminals. This directly results in savings by reducing the required inventory.