Smart SSI

SLM - Solid Level Switches

SLM series vibrating forks are point-level limit switches for free flowing solids, granules,  and powders. These are available with explosion-proof housings for hazardous areas.

Principle

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 or control.

Features
  • Power Consumption: Less than 05 VA
  • ­Power Supply: 24V DC, Universal (90-260 V AC)
  • High temperature durability (H2 – up to 200°C )
  • Independent of material’s electrical properties
  • Suitable for detection of underwater chips
Mechanical Specifications

Resonant Frequency

  •  85 Hz

Probe Length

  • Extensible probe length from 155 mm up to 3000 mm

Enclosure

  • W: Weatherproof
  • P5: IP-65 Weatherproof housing
  • FA: Flame-proof for Gas Groups IIA and IIB

Model

  • Integral version (Electronics Integral with fork)
  • Split version (Electronic separated by a special cable)
  • Separate version (Electronics separated by ordinary 03 core cable)

Process Connection(Mounting Arrangement)

  • Threaded Mounting: 1-1/2”, 2” BSP/NPT
  • Flanged Mounting: As per specification
  • Tri-Clover (as per specifications)
  • SMS union coupling type

Extension Length

  • Pipe- GI/SS: 155 mm – 3000 mm

Probe Length

  • Extension Length + Fork Length (155mm / 185mm / 250mm)

Wetted Parts and Mounting Material

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

Process Temperature

  • A (Ambient) below 80°C
  • H1 (High temperature) up to 150°C
  • H2 (High temperature) up to 200°C
Electrical Specifications

Input power supply & Outputs

  • SLM 130/120/110: Single SPDT with (90 – 260 V AC) / 230 V AC / 24 V DC
  • SLM 130/120/110: One open collector PNP transistor with 24 V DC
  • SLM 230/220/210: Double SPDT with (90 – 260 V AC) / 230 V AC  / 24 V DC
  • SLM 330/320/310: Single SPDT & Time Delay with (90 – 260 V AC) / 230 V AC / 24 V DC
  • SLM 630/620/610: Double SPDT & Time Delay with (90 – 260 V AC) / 230 V AC / 24 V DC

Power Consumption

  • 05 VA

Fail-safe Setting

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

Response Time

  • 02 – 05 Sec

Time Delay Settings

  • Cover and Uncover Delay: 02s to 20s, through toggle switches

Sensitivity Setting

  • Field Selectable (through toggle switches)
Applications Specifications

Application Material

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

  • Powders, sand, sugar
  • Pulverized coal
  • Food grains
  • Cement
  • Granular material
Certifications
  • Flame Proof Housing IIa / IIb certified by CMRI, Dhanbad
  • CE certification
  • IP-65 from ETDC Indore
  • ISI mark from the Bureau of Indian Standards.
Switching Indication
  • 2 LED’s
  • Red: Alarm, Green: Normal